Plaster Resource Manual

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					           ®       09 23 00/NGC
Gold Bond BRAND    09 26 13/NGC

Plaster Resource
Table of Contents                                                                                    How to use                                We’ve even included a glossary of
                                                                                                     this Manual                               plaster terms and definitions.
    SECTION                                                                              PAGE
                                                                                                     Designed for contractors, architects      For technical inquiries, contact our
Lath & Plaster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3                                                Technical Services Department at
                                                                                                     and specifiers, this useful manual
    Gypsum Plaster Base and Metal Lath . . . . . . . . . . . . . . . . . . .4                        contains a broad range of helpful         1-800-NATIONAL (628-4662), or
                                                                                                     information about our lath and            fax 1-800-FAX-NGC1 (329-6421).
    Conventional Plaster Accessories . . . . . . . . . . . . . . . . . . . . . . .5                  plaster systems and veneer plasters.      You can also access our Internet
                                                                                                                                               home page at
    Basecoat Plasters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6       Since conventional lath and plaster       or
                                                                                                     differs from veneer plaster, we’ve
    Finish Plasters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7   simplified the manual by dividing it      Note: Further information on our
                                                                                                     into two distinct sections.               plaster products is available in
    Problems & Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
                                                                                                                                               National Gypsum Company’s
                                                                                                     The first section contains descriptions   Gypsum Construction Guide.
Veneer Plaster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
                                                                                                     of our gypsum plaster systems including
    Veneer Plaster System Components . . . . . . . . . . . . . . . . . . .14                         lath, metal accessories and plasters.
                                                                                                     You’ll also find construction recom-
    Veneer Plaster Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . .16               mendations to help you get the
    Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
                                                                                                     most from this conventional finish.
                                                                                                     The second section, devoted to
    Problems & Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21           veneer plaster, features descriptions
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26   of our products including Uni-Kal®,
                                                                                                     X-KALibur® and Kal-Kote®, along
                                                                                                     with a comparison of one-coat and
                                                                                                     two-coat systems.
                                                                                                     In both sections, we look at unique
                                                                                                     conditions common to plaster finishes,
                                                                                                     and we recommend solutions to
                                                                                                     these problems.

Lath & Plaster                                                                                                                                    09 23 00/NGC

                                                                                    Features/Benefits                        Recommendations
                                                                                       Provides a smooth, high quality        Control joints should be installed
                                                                                       surface                                in ceilings without perimeter
                                                                                       Requires no joint taping and           relief with a maximum distance
                                                                                       finishing                              between joints of 30' with a
                                                                                                                              maximum undivided area of
                                                                                       Resists nail pops better than          900 sq. ft. With perimeter relief,
                                                                                       gypsum wallboard                       the maximum distance between
                                                                                       Enhances overall wall strength         joints is 50' with a maximum
                                                                                                                              undivided area of 2500 sq. ft.
                                                                                       High impact and abrasion
                                                                                                                              On side walls, control joints
                                                                                                                              should be installed every 30'.
                                                                                       Masks framing components and
                                                                                                                              Where dissimilar plaster bases
                                                                                       mechanical service areas
                                                                                                                              adjoin, use strip-metal lath with
                                                                                    Selecting Plaster                         15 lb. felt paper between the
                                                                                    Bases                                     metal lath and underlying base.
                                                                                    National Gypsum Company manu-             Carefully inspect all lath and fur-
                                                                                    factures all of the most common           ring before plastering to ensure
                                                                                    types of gypsum base plaster and          adherence to job specifications
                                                                                    finishing plaster.                        and good practice standards.
                                                                                    These products perform well               Select from the suggested
                                                                                    in appearance, structural ability,        specifications that accompany
Description                              General Uses                               sound isolation and fire endurance        the description of each system.
Conventional gypsum lath and             Gypsum plaster systems are suit-           ratings, allowing architects to
                                                                                                                             PRODUCT SHELF LIFE
plaster systems have long been           able for all interior plastering           design virtually any number of
                                                                                    ceilings and partitions.                                          Storage/
considered the industry standard in      except areas directly exposed to                                                    Product                 Shelf Life
wall construction.                       free water or severe moisture. Lath
                                         and plaster is not recommended             Performance                              Two-Way Hardwall          3 months
Ideal for both residential and                                                                                               Gypsolite® Plaster        3 months
commercial applications, lath and        for exterior applications such as          The relative performance of gypsum
                                                                                                                             Gauging Plaster           3 months
plaster systems provide smooth,          carports, soffits and open porches.        and metal lath varies depending
                                                                                    on the type of construction. When        Molding Plaster           3 months
high quality wall surfaces, regardless   Gypsum plasters are non-com-
of framing alignment.                    bustible and act to prevent passage        plaster on metal lath forms a mem-
                                         of intense heat from fire for extend-      brane, as in a suspended ceiling or
Lath and plaster deliver exceptional                                                hollow partition, it’s more subject to
beauty and durability in interior        ed periods. For specific fire resistance
                                         ratings, see National Gypsum’s             cracking than plaster on gypsum
partitions and non-loadbearing                                                      lath. On solid partitions, metal lath
exterior walls. Conventional plaster     Gypsum Construction Guide.
                                                                                    is generally less subject to plaster
systems are also commonly used                                                      cracking than gypsum lath.
as the panel material for radiant
heating systems in ceilings.
When used with expanded metal
lath, conventional plasters create a
mechanical bond for maximum
strength and durability. Gypsum
plasters are also excellent for
sculpting, casting decorative
objects, and historic restoration.

Gypsum Plaster Base and Metal Lath

Kal-Kore® BRAND Plaster Base                                                      Metal Lath Products*
                                                                                                                              DIAMOND MESH LATH
                                                                                                                              Used as a plaster base and rein-
                                                                                                                              forcement on almost all types of
                                                                                                                              walls and ceilings, over wood or
                                                                                                                              steel framing, flat or curved surfaces.

                                                                                                                              SELF-FURRING DIAMOND
                                                                                                                              MESH LATH
                                                                                                                              Used extensively in stucco work, as
                                                                                                                              a plaster reinforcement over interior
                                                                                                                              masonry walls, and in steel column
                                                                                                                              fireproofing. The self-furring dimples
                                                                                                                              hold the metal lath 1/4" away
                                                                                                                              from the surface to be plastered.

Description                              Technical Data                                                                       1/8" FLAT RIB LATH

Kal-Kore BRAND is a tapered edge
                                         Kal-Kore is available in two basic                                                   Designed to meet the demand for
gypsum wallboard plastering base         types: Regular and Fire-Shield Type X.                                               rigid expanded metal lath used as
having a blue absorptive face            Kal-Kore is 4' wide and is supplied in                                               a plaster base in all types of work.
paper surface. Although specifically     8' through 16' lengths.Thicknesses                                                   Widely used as reinforcement for
designed as a base for veneer plaster,   are as follows:                                                                      basecoat in ceramic tile work.
it also provides an excellent base       Regular: 3/8" and 1/2".
for conventional basecoat plasters
such as Gypsolite or Two-Way             Fire-Shield: 1/2" Fire-Shield G,
Hardwall.                                5/8" Fire-Shield, 5/8" Fire-Shield
                                         G, produced to meet ASTM
                                         C 588/C 1396.                                                                        3/8" RIB LATH
                                         Note: Installation of gypsum lath                                                    The 3/8" rib lath is used for ceilings
                                         and metal lath shall be in accor-                                                    under steel joist construction and
                                         dance with ASTM C 841. Do not                                                        metal reinforced concrete floors. It
                                         use 3/8" Kal-Kore Plaster Base with                                                  is also recommended for concrete
                                         conventional basecoat plasters.                                                      slab floors over steel joists.

                                                                                  * Metal products are not manufactured by National Gypsum Company.
Conventional Plaster Accessories*

                                            DOUBLE V EXPANSION JOINT                 BULL NOSE CORNERBEAD
                                            Minimizes cracking in large plaster      Reinforces exterior corners where
                                            areas. Also provides ground to           rounded edges are required. Nose
                                            assure proper plaster or stucco          3/4" radius. Galvanized steel.

                                            DOUBLE V CORNER                          WIDE FLANGE EXPANDED
                                            EXPANSION JOINT                          CORNERBEAD
                                            Similar in design to Double V            Has 3-3/16" expanded flanges for
                                            expansion joint but preformed to         use on masonry, beams and for
                                            fit corner angles. Galvanized steel      column fireproofing. Galvanized
                                            or zinc.                                 steel.

                                            EXPANSION JOINT                          L RUNNER
                                            Designed to relieve stresses in          Perforated – Ceiling or floor
                                            large gypsum and portland cement         support for 2" solid lath
                                            plaster areas. Material will expand      and plaster partition.
                                            and contract to allow for 1/8" to        Plain – Ceiling support for 2"
                                            5/8" opening. Incorporates a             solid wallboard partition using 1"
                                            weather resistant joint. Galvanized      shaftliner.
                                            steel or zinc.

                                            EXPANDED FLANGE                          COLD ROLLED STEEL
                                            SQUARE CASING                            CHANNEL
                                            Has short, 90 degree return at plaster   Used as studs for attaching metal
                                            surface, serving as a plastering stop.   lath in 2" solid partitions. For furring
                                                                                     or runners in suspended ceilings.

                                            EXPANDED CORNERBEAD                      BEAM FURRING CLIP
                                            The 2-1/2" expanded flange ends          Used to attach lath to flanges of
                                            1/4" from the nose of the bead           steel beams, joists and columns.
                                            providing reinforcement where            Tempered spring steel.
                                            needed most.

* Metal products are not manufactured by National Gypsum Company.
Basecoat Plasters

Gold Bond ® BRAND                                                                     Gold Bond® BRAND
Two-Way Hardwall Gypsum Plaster                                                       Gypsolite® Plaster
Description                                                                           Description
Gold Bond Two-Way Hardwall
                                                                                      Gold Bond® Gypsolite® is a light-
Plaster is a basecoat plaster which                                                   weight gypsum basecoat plaster
requires the job site addition of an                                                  mixed at the mill with correctly
aggregate and water to provide                                                        sized and proportioned perlite
working qualities and is designed                                                     aggregate, requiring only the
for interior use over all accepted             Strength                               addition of water on the job. It        High Insulating Value
plaster bases. It may be applied by            Two-Way Hardwall Plaster properly      is manufactured to be trowel-           Gypsolite has a “k” factor of 1.5
hand or used through pump/ spray               proportioned with aggregate forms      applied over gypsum plaster base,       which provides about 3-1/2 times the
plastering machines.                           a hard, durable base for the finish    and in some cases metal lath            insulating value of sanded plaster.
                                               coat. Its high tensile and compres-    (see LIMITATIONS.)
Features/Benefits                              sive strength results in increased
                                                                                                                              Fire Resistance
Controlled Uniformity                          resistance to minor structural
                                                                                      Features/Benefits                       Gypsolite has excellent fire-resistive
                                                                                                                              qualities and generally provides fire
Two-Way Hardwall Plaster is set-               movements, impacts and abrasions.      Uniform Strength and
                                                                                                                              ratings higher than sanded plaster.
stabilized and adjusted for market                                                    Hardness
                                               Fire Resistance
requirements and seasonal changes.                                                    Uniformity is assured through exact     Limitations
                                               Two-Way Hardwall Plaster is
When mixed with sand or other                                                         proportioning and thorough mixing
                                               essentially mineral in composition                                             When used over metal lath, a sand
aggregate it has uniform working                                                      of graded perlite and gypsum plas-
                                               and will not support combustion.                                               float finish should be specified. A
qualities and excellent spread.                                                       ter at the mill. Gypsolite provides a
                                                                                      uniform base for the finish coat.       smooth-trowel finish is not recom-
                                                                                                                              mended since the combination of a
Technical Data                                                                        Lightweight                             relatively soft (perlite aggregated)
                                                                                      Gypsolite weighs less than half         basecoat and a hard (smooth-
    AGGREGATE PROPORTION AND ESTIMATED COVERAGE                                       as much as sanded gypsum plaster,
                                   Coverage,              Sq. Ft.           Thick-
                                                                                                                              trowel lime/gauging) finish has the
    Aggregate                     Sq. Yds. /Ton          (Sq. M.)             ness
                                                                                      thus reducing the dead-load on          potential for cracking and spalling
    Proportions Plaster Base (Sq. M./Metric Ton)         per Bag           In. (mm)   framing.                                of the finish coat.
    Sanded       Gypsum Lath        175-220               80-100             7/16"
    1:2-1/2                        (161-203)               (7-9)             (11.1)
    Sanded        Gypsum Foil       175-220               80-100             7/16"
                                                                                      Technical Data
    1:2-1/2        Back Lath       (161-203)               (7-9)             (11.1)    GYPSOLITE ESTIMATED COVERAGE
    Sanded         Metal Lath        90-125                40-55            9/16"*                                Coverage,         Sq. Ft.           Thickness
    1:2-1/2                         (83-115)               (4-5)            (14.3)*                           Sq. Yds. per Ton     (Sq. M.)                In.
    Sanded      Brick & Clay Tile   175-220               80-100             9/16"     Plaster Base          (Sq. M/Metric Ton)    per Bag               (mm)
    1:3         Concrete Block     (161-203)               (7-9)             (14.3)    Gypsum Lath and              140-155         50-55                7/16"
                                                                                       Gypsum Foil Back Lath       (129-143)         (4-5)               (11.1)
*Measured from face of lath.
NOTE: Sanded 1:2-1/2 means 1 part plaster to 2-1/2 parts sand by weight.               Metal Lath                    65-80          25-30               9/16"*
                                                                                                                    (60-74)          (2-3)              (14.3)*
    WEIGHT COMPARISON OF BASECOAT PLASTERS                                            *Measured from face of lath.
    Dry Set Mortar Weight                      Sanded 1:3             Gypsolite
    Weight lbs. per cu. ft. (kg/m3)             120 (1922)             50 (801)       Specification Reference
                                                                                      ASTM Designation C 28, “Gypsum
      Lbs./yd.2 (kg/m2) 3/8" (9.5 mm) thick      34 (18)                14 (8)
      Lbs./yd.2 (kg/m2) 1/2" (12.7 mm) thick     45 (24)               19 (10)        Plasters”.
      Lbs./yd.2 (kg/m2) 5/8" (15.9 mm) thick     56 (30)               24 (13)
      Lbs./yd.2 (kg/m2) 3/4" (19.0 mm) thick     67 (36)               29 (16)        Bag Weight
    Wet Mortar Weight                                                                 80 lbs. (36.3 kg)
                                                                                      25 lbs. (11.3 kg)
    Weight lbs. per cu. ft. (kg/m3)             140 (2243)            69 (1105)

Specification Reference
ASTM Designation C 28, “Gypsum
Bag Weight
100 lbs. (45.4 kg)

Finish Plasters

 Plaster                             Gypsolite           Two-Way Hardwall to                         Two-Way Hardwall                            Two-Way Hardwall
 Properties                           Regular              Sand by Weight                             and Vermiculite                                and Perlite
                                                                                              Regular             Masonry                 Regular              Masonry
 Mix                                  Mill Mix          1:1         1:2         1:3       100 lbs. (45.4 kg) 100 lbs. (45.4 kg)       100 lbs. (45.4 kg) 100 lbs. (45.4 kg)
                                                                                           2 cu. ft. (.06 m3)  3 cu. ft. (.08 m3)      2 cu. ft. (.06 m3)   3 cu. ft. (.08 m3)
 Approximate Compressive                900            1600        1150         750               500                 300                     900                  650
   Strength lbs. per sq. in. (kPa)     (6201)        (11024)      (7923)      (5168)            (3445)              (2067)                  (6201)               (4479)
 Approximate Tensile                    160             250         190         120               130                  90                     160                  100
   Strength lbs. per sq. in. (kPa)     (1102)         (1722)      (1309)       (827)             (896)               (620)                  (1102)                (689)

Gold Bond ® BRAND                                                                        Gold Bond ® BRAND
Gypsum Gauging Plaster (Super White)                                                     Gypsum Moulding Plaster (Super White)
Gold Bond Gauging Plaster, quick set                                                     Gold Bond Moulding Plaster is a very
or slow set type, is designed for use                                                    white, finely ground gypsum, primarily
with finish lime. It is specially ground,                                                used for all kinds of ornamental
calcined gypsum, which readily mixes                                                     plaster work. Because of its low
with water and lime putty. Proper                                                        expansion, excellent strength and
proportioning is essential, since                                                        hardness, it is specially adaptable for
gauging adds strength and hardness                                                       casting in rubber, gelatin and other
to the finish surface by reinforcing            gypsum plaster basecoat. Smooth          types of moulds. For casting purposes,       Specification Reference
the plastic non-setting lime against            finish plasters should be applied at a   only water is added. For run-in-place        Complies with ASTM Designation
shrinkage and cracking.A finish coat            thickness of not more than 1/16".        ornamental work, such as cornices,           C 59.
of gypsum gauging plaster and finish            Texture finishes should be applied at    the moulding plaster is used with lime       Note: Application of plaster shall
lime, job mixed 2 parts hydrated lime           a thickness of not more than 1/8".       putty, mixed 2 parts lime to 1 part          be in accordance with ASTM C 842.
to 1 part plaster by weight, is                 Specification Reference                  moulding plaster by weight.
designed primarily for interior                 Complies with ASTM Designation
smooth trowel application over a                C 28.                                    Technical Data
                                                                                          GYPSUM MOULDING PLASTER
Technical Data                                                                            Method of Application                            Coverage*
 GYPSUM GAUGING PLASTER                                                                   Trowel Finish                   1000-1400 sq. yds./Ton (921-1290 m2/Metric Ton)
 Method of Application                  Coverage*                                                                               225-315 sq. ft./Bag (21-29 m2/Bag)
 Trowel Finish         1000-1400 sq. yds./Ton (921-1290 m2/Metric Ton)                   *Based on one part plaster to two parts hydrated lime.
                             225-315 sq. ft./Bag (21-29 m2/Bag)
*Based on one part plaster to two parts hydrated lime.                                   Bag Weight
                                                                                         100 lbs./45.4 kg (50 lbs./22.7 kg
Bag Weight                                                                               bags available in limited areas)
Quick Set: 100 lbs./45.4 kg                     Slow Set: 100 lbs./45.4 kg
(50 lb./22.7 kg bags available in               (50 lb./22.7 kg bags
limited areas)                                  available in limited areas)

Mill-Mixed Finish Plasters
For a mill-mixed finish plaster, use            Extended Set Veneer Plaster.
Kal-Kote Smooth Finish, Kal-Kote                Requires the addition of water
Texture Finish Plaster, Uni-Kal                 only. See page 17.
Veneer Plaster or X-KALibur
                                 Method of
 Product                         Application                   Coverage*
 Kal-Kote Smooth Finish            Trowel                   650-750 sq. yds./Ton
                                                          (598-645 m2/Metric Ton)
 Kal-Kote Texture Finish             Trowel                 650-750 sq. yds./Ton
                                                          (598-645 m2/Metric Ton)
 Uni-Kal and X-KALibur               Trowel                 600-665 sq. yds./Ton
                                                          (553-613 m2/Metric Ton)
*See page 17 for additional information.

Lath & Plaster Problems and Solutions

Conditions/Causes/                         Cracks*                              The cause(s) of these generally are          Environmental job conditions
Prevention/Correction                      Surface defects, blemishes, stains   the result of:                               Poor or improper plastering
                                           Weak or soft plaster                    Conditions relating to plaster set        practices and workmanship
Plaster problems are rarely caused by
                                           Bond failure                            Poor quality or incorrect propor-
a gypsum plaster product deficiency.                                                                                    *Conventional plaster, although not con-
                                                                                   tioning of aggregate                 sidered to be a structural member, is not
In general, most conventional plaster      Finish coat problems
                                                                                   Structural movement                  delicate construction and can endure con-
construction problems can be               Working qualities and setting                                                siderable abuse without cracking. However,
classified into one of the following       action                                  Improper mixing, application or      cracks can occur when excessive external
categories.                                                                        thickness of basecoat or finis       forces caused by structural or component
                                           Painting plaster                                                             movement over which the plaster is applied
                                                                                   Incorrect or improper lathing or     are transmitted to the plaster or by extreme
                                                                                   substrate                            environmental changes.

                                                                                   Dirty mixing equipment

Condition                       Construction                    Probable Cause                  Preventive Action                Corrective Action
Connected Vertical              Plaster applied over            1. Plaster too thin.            Properly install lath, use       1. Apply another coat of
And Horizontal Cracks           gypsum or metal lath.           2. Weak plaster (too much       properly sized and propor-          plaster to proper thickness.
Occurring At Somewhat                                              or improper aggregate.)      tioned aggregate and apply       2. Remove defective plaster
Regular Intervals,                                              3. Lath improperly applied.     plaster to the required             work and replace with
Usually In A Stepped                                                                            thickness.                          properly proportioned
Or Grid Pattern                                                                                                                     plaster.
                                                                                                                                 3. Check Lathing Specifica-
                                                                                                                                    tions, remove and reapply
                                                                                                                                    lath properly and replaster.

Cracks Around And               Plaster over masonry, cement 1. Poor construction of lintel,    Follow proper construction       1. Patch cracked areas.
Over Openings Such As           block, gypsum tile or gypsum,    door bucks improperly          installation practices.          2. Apply coat of plaster to
Doors Or Windows                wood or other sheet lath.        constructed or installed.                                          proper thickness.
                                                              2. Plaster too thin.                                               3. Remove plaster and provide
                                                              3. Failure to use reinforcing.                                        expanded metal rein-
                                                              4. Expansion of wood or                                               forcement and replaster.
                                                                 metal framing.                                                  4. Remove plaster, provide
                                                              5. Weak plaster, too much                                             control joints, replaster.
                                                                 aggregate.                                                      5. No correction – remove
                                                                                                                                    and replaster.

Fine Cracks Occurring           1. Basecoat over masonry,       1. Basecoat too rich,           Follow proper plastering         1. Remove plaster and redo
In A Random Pattern                cement block, etc.              insufficient aggregate.      practices.                          properly.
Usually Less Than               2. Lime putty finish over       2. Basecoat too dry when                                         2. Prepare basecoat by spraying
6" Apart. Shrinkage                gypsum basecoat.                finish applied – excessive                                       with water to decrease suction.
Cracks, Crazing,                                                   suction.                                                      3. Strip finish, replaster with
Alligatoring, Chip                                              3. Insufficient or slowset                                          proper gauging.
Cracks                                                             gauged finish.                                                4. Strip finish and correctly
                                                                4. Finish applied too thick.                                        refinish.
                                                                5. Insufficient troweling of                                     5. Strip finish and tightly scratch,
                                                                   finish.                                                          apply 1/32" - 1/16" thick.

Random Cracks In Wall           Plaster over any                Structural movement.            Use a properly designed          Repair cracks.
Or Ceiling, Generally           substrate.                                                      and installed construction       Large Cracks: Remove plas-
Running Full Length Of                                                                          such as a suspended or           ter about 6" on each side of
Wall Or Width Of                                                                                floating plaster system.         the crack down to the sub-
Ceiling. May Adjoin                                                                                                              strate. Place a strip of metal
Other Cracks And Are                                                                                                             lath in the cleared area, wet
Generally Widely                                                                                                                 with water and replaster.
Spaced                                                                                                                           Small Cracks: Open the
                                                                                                                                 crack slightly, wet and fill
                                                                                                                                 flush with a setting type
                                                                                                                                 joint compound.

Condition                   Construction                   Probable Cause                     Preventive Action                 Corrective Action
CRACKS (cont.)
Cracks At Wall Or           1. Plaster over gypsum lath.   1. a. Thin plaster.           1. a. Be sure proper plaster- 1. a. Apply second coat of
Ceiling Angles              2. Plaster over masonry.          b. Failure to use expanded    ing grounds are in place.     plaster to proper thickness.
                                                              metal reinforcement.          b. Always apply expanded      b. Cut out plaster and
                                                              c. Structural movement.       metal reinforcement in all    patch.
                                                           2. Failure to tie walls          interior angles.              c. Patch cracks.
                                                              together.                     c. Follow proper construc- 2. Patch cracks.
                                                                                            tion practices.
                                                                                         2. Follow proper construction

Cracks Not Due To Any       1. Plaster over metal or       1. a. Metal lath too light.        Follow proper construction        1. a/b. Remove lath and
Of The Previously              gypsum lath.                   b. Metal lath not lapped        practices.                           plaster, apply proper
Mentioned Causes And        2. Plaster over metal or          or properly tied.                                                    weight lath and replaster.
Are Not The Result Of          gypsum lath on steel           c. Thermal shock.                                                    c. Patch cracks.
Structural Movement            framing.                    2. a. Improper spacing of                                            2. a. Remove plaster, properly
                                                              framing members.                                                     space framing and replaster.
                                                              b. Thermal shock.                                                    b. Patch plaster.
Fuzz (Efflorescence) On     Basecoat or finish coat over Efflorescence – water soluble        Fur wall away from the       Eliminate the source of
Surface,White Or Colored,   masonry or concrete substrate. salts are deposited on the         masonry or concrete prior to moisture.
Is Water Soluble And Can                                   surface of the plaster as the      plastering.
Be Removed By Brushing                                     masonry or concrete dries.

Streaky Discoloration       Lime putty finishes gauged     1. Use of too much water           1. Use proper amount              1–3. Paint plastered sur-
                            with gauging plaster or           while troweling.                   of water while troweling.         faces with a good quality
                            Keene’s cement.                2. Improperly/poorly mixed         2. Thoroughly mix the lime           paint as recommended
                                                              lime and gauging material.         and gauging.                      by the paint manufactur-
                                                           3. Dirty tools, water, or mixing   3. Use only clean tools, mixing      er.
                                                              equipment.                         equipment and water.           4. See correction for FUZZY
                                                           4. Efflorescence.                  4. See prevention for FUZZY          surface.

Streaked Finish, Joinings   Finish plaster over any sub-   1. Too much water used             Use only the proper amount        Prime and paint surface
Showing, Dirty Areas        strate.                           while troweling.                of clean water during trow-       with a good quality paint as
                                                           2. Use of dirty water during       eling.                            recommended by the paint
                                                              troweling.                                                        manufacturer.

Blisters On Finish Coat     Gauged lime putty or mill      1. Basecoat too green (wet). 1/2. Allow basecoat to dry        Remove blistered finish and
(Entrapped air between      mixed gypsum plaster trowel    2. Insufficient suction.        sufficiently to develop        replaster.
finish and substrate)       finishes.                      3. Too much water used          proper suction.
                                                              while troweling.          3. Dash water on surface
                                                           4. Insufficient gauging.        sparingly during troweling.
                                                           5. Troweling before suffi-   4. Use proper proportions of
                                                              cient take-up.               lime putty and gauging.
                                                                                        5. Allow plaster to take-up
                                                                                           sufficiently before troweling.

Projections On Surface      Finish or basecoat plasters    Unslaked lime or foreign           Use Type S hydrated lime or       Remove the core of the
Which Fall Out Leaving      containing lime.               matter in the plaster which        properly soak lime to insure      crater or pits and patch
Craters Or Pits. May Have                                  hydrates and expands after         proper hydration.                 with finish plaster or ready
Fine Cracks Radiating                                      application.                                                         mix joint compound.
From The Center

Condition                 Construction                  Probable Cause                  Preventive Action                  Corrective Action
Soft, White, Chalky       Basecoat over any             Usually occurring during        Screen openings to minimize        Spray dried out areas with
Surface                   plaster base.                 dry, hot weather. Too much      drafts during dry, hot weather     water or a solution of alum
                                                        ventilation has removed water   and spray the surfaces and         (1 lb. alum per 3 gallons of
                                                        from the plaster before it      floors with water during the       water).
                                                        has set. Called “dry-out”.      setting period.

Soft, Dark, Damp          Basecoat over any             1. DAMP WEATHER - too           1. Maintain proper heating 1. Dry plaster by ventilating
Plaster Surface           substrate.                       little ventilation during       and ventilating prior to,     and heating. If condition
                                                           damp weather, water             during and after plastering.  has existed for too long
                                                           remaining in plaster too     2. Maintain minimum 55˚F         it cannot be corrected.
                                                           long after set has              prior to, during and after    Plaster must be removed
                                                           occurred, “Sweat-Out”.          plastering and provide        and replastered.
                                                        2. FREEZING WEATHER                adequate ventilation until 2. Close building, heat
                                                           CONDITIONS – FROZEN             plaster is dry.               building until plaster sets
                                                           PLASTER                                                       and continue heating
                                                                                                                         and ventilating after set.

Weak, Soft Plaster, Due   Gypsum basecoat over any      1. Too fine or poor aggre-      Use only aggregate meeting No correction – remove the
To Improperly Propor-     plaster base.                    gate grade.                  ASTM specification. Properly plaster and replaster.
tioned Aggregate                                        2. Too much aggregate.          proportion aggregate and
Separation Of Basecoat    Basecoat over gypsum lath.    1. Too much or improper         1. Use only proper and           No correction – remove the
From Gypsum Lath                                           aggregate used.                 ASTM-specified plaster/       plaster and replaster.
                                                        2. Frozen plaster.                 aggregate proportions.
                                                                                        2. Maintain a minimum temper-
                                                                                           ature of 55˚F in the building
                                                                                           prior to, during and after
                                                                                           application and provide
                                                                                           adequate ventilation.

Separation Of Basecoat    Basecoat over metal lath.     1. Too much or improper         1. Use only proper and             No correction – remove the
From Metal Lath                                            aggregate.                      ASTM-specified plaster/         plaster and replaster.
                                                        2. Frozen plaster.                 aggregate proportions.
                                                        3. Scratch coat too thin.       2. Maintain a minimum tem-
                                                                                           perature of 55˚F in the
                                                                                           building prior to, during and
                                                                                           after application and pro-
                                                                                           vide adequate ventilation.

Separation Of Basecoat    Basecoat over unit masonry.   1. Excessive suction of the     1. Dampen the masonry to           No correction – remove the
From Unit Masonry                                          masonry base.                   reduce suction.                 plaster and replaster.
                                                        2. Masonry base has a           2. Roughen the masonry
                                                           non-absorbent or glazed         surface to provide a key
                                                           surface.                        for the plaster.
                                                        3. Efflorescence present on     3. Eliminate the source of
                                                           the masonry base.               moisture causing the efflo-
                                                                                           rescence. Fur away from
                                                                                           the masonry surface and
                                                                                           apply lath over the furring.

Condition                  Construction                  Probable Cause                   Preventive Action                 Corrective Action
Separation Of Gypsum       Basecoat over monolithic      Concrete bonding agent not Apply plaster bonding agent             No correction – remove the
Plaster From Monolithic    concrete.                     applied.                   per ASTM specification –                plaster and replaster.
Concrete Surface                                                                    before application of plaster.

Brown Coat Plaster         Three-coat plaster work.      1. Weak scratch coat plaster.    1. See preventive actions         No correction – remove the
Separating From                                          2. Failure to provide adequate      under weak, soft plaster.      plaster and replaster.
Scratch Coat Plaster                                        mechanical keying to          2. Do not over trowel
                                                            scratch coat.                    scratch coat; rake or
                                                                                             broom scratch coat to pro-
                                                                                             vide mechanical keying.
Gauged Lime Putty          Gauged lime finish over       1. Brown coat too weak,          1. Make sure brown coat is 1. No correction – remove
Finish Coat Separating     basecoat.                        too smooth, too wet (too         properly prepared to        finish coat, correct condi-
From Brown Coat Plaster                                     little suction) or too dry       receive finish.             tion of brown coat and
                                                            (too much suction).           2. Apply finish, taking pre-   replaster.
                                                         2. Finish applied improperly.       cautions to follow recom- 2/3. No correction – remove
                                                         3. Incomplete hydration of          mended practices.           finish coat and replaster.
                                                            finish lime.                  3. Use only Type S hydrated
                                                                                             lime and mix according
                                                                                             to recommendations.

Gypsum Sand Float Or       Gypsum sand finish over       1. Brown coat too weak.          Make certain that the brown 1. No correction – remove
Trowel Finish Separating   basecoat.                     2. Brown coat too dry.           coat is sound, not overly dry       finish, correct brown coat
From Brown Coat                                          3. Brown coat too smooth.        and has adequate roughness          condition and replaster.
                                                                                          to provide keying to the finish. 2. No correction – remove
                                                                                                                              finish, spray brown coat
                                                                                                                              with water to reduce suc-
                                                                                                                              tion and replaster.
                                                                                                                           3. No correction – remove
                                                                                                                              finish, roughen brown
                                                                                                                              coat to provide adequate
                                                                                                                              keying and replaster.

Finish Coat Weak, Soft     Gypsum finish over basecoat. 1. Insufficient gauging           1. Use proper proportions         No correction – remove the
                                                           plaster used.                     of gauging to lime putty.      plaster and replaster.
                                                        2. Retempered finish coat.        2. Do not retemper plaster
                                                        3. Inadequate or insufficient        that has started to set.
                                                           troweling of the finish.       3. Lime putty finishes must
                                                                                             be troweled sufficiently
                                                                                             to densify the finish and
                                                                                             develop proper strength.

Lime/Gauging Finish –      Gauged lime finish over       1. Old material, warehoused      1. Use only fresh lime which There is no correction for
Tough, Short Working       basecoat.                        too long or improperly.          has been properly ware- these occurrences.
Or Lumpy Lime Putty                                      2. Lime improperly mixed or         housed.
                                                            soaked.                       2. Mix and/or soak lime
                                                         3. Low temperatures.                according to supplier’s
                                                                                          3. Maintain proper temper-
                                                                                             ature above 55˚F prior to,
                                                                                             during and after plastering.

Set Not Uniform            Gypsum finish over            1. Improper gauging plaster      1. Use either Quick or Slow       There is no correction for
                           basecoat.                        used.                            set gauging in the proper      these occurrences.
                                                         2. Temperature conditions           proportions.
                                                            too hot or cold.              2. Maintain proper temper-
                                                                                             ature above 55˚F prior to,
                                                                                             during and after plastering.
Condition                       Construction                     Probable Cause                     Preventive Action            Corrective Action
Finish Coat                     Gypsum finish over               1. Basecoat plaster too dry.       Follow good plastering       1. Apply finish coat over
Works Hard                      basecoat.                        2. Finish coat mixed too           practices.                      green base or spray the
                                                                    stiff.                                                          dry base lightly with
                                                                                                                                    water before finishing.
                                                                                                                                 2. Use correct amount of water
                                                                                                                                    when mixing finish coat.
Slow Plaster Sets –             Basecoat plaster over any        1. Retarding action of        Use only proper plaster           1/2. Obtain good sand and
Not Set After Five Or           substrate.                          aggregate.                 aggregate, potable water             water or accelerate
Six Hours                                                        2. Retarding action of water and fresh plaster.                    mixes.
                                                                    being used.                                                  3. Replace with fresh plaster
                                                                 3. Old plaster set lengthened                                      or accelerate mixes.
                                                                    due to aging.

Plaster Sets Too Quickly        Basecoat plaster over any        1. Tools and mixing equip-         Keep tools and mixing        1–3. Judiciously use
To Be Darbied Or Sets           substrate.                          ment not free of set plaster.   equipment clean, use only       retarder to slow setting,
In Mortar Box Or On                                              2. Dirty or contaminated           potable water and clean         clean equipment and
The Board                                                           sand or water.                  sand for mixing. Use fresh      obtain clean water and
                                                                 3. Plaster too old or became       plaster which has been          sand.
                                                                    wet in storage or on the        stored properly. Follow      4. Reduce plaster mixing
                                                                    job site.                       good plastering practices.      time.
                                                                 4. Plaster being mixed too

Plaster Works Hard Or           Basecoat plaster over any        1. Plaster is old or stored        Use only fresh, properly     1. Blend equal parts of
Short, Will Not Spread,         substrate.                          under poor conditions.          stored plaster.                 fresh and old plaster.
Will Not Carry Proper                                            2. Too much or improper                                         2. Use proper aggregate at
Amount Of Aggregate                                                 aggregate being used.                                           proper proportions.

Painting Plaster
Various job conditions such as suction differences, wet or only partially dry
walls, and reactions between paint and lime may cause unsatisfactory
paint finishes, particularly on new construction.
Alkali-resistant primers specifically formulated for use over new plaster will
permit decorating with oil or latex type paints.
Quality paint products should be used and manufacturers’ recommendations
followed. Finished plaster should be painted or covered to conceal possible
discoloration. The paint system should be suitable for use over plaster
surfaces that contain lime.
It is essential that plaster be sound and completely dry before painting.
Conventional plaster may require 30 to 60 days to fully dry.

Veneer Plaster                                                                                                                             09 26 13/NGC

                                                                                 Two-Coat System                        All are designed for trowel
                                                                                 Features/Benefits                      application. Veneer Plasters are
                                                                                 (Kal-Kote® BRAND)                      not suitable for conveyance or
                                                                                   Kal-Kote System may be used          application by conventional
                                                                                   for plaster-embedded electric        plastering machines.
                                                                                   radiant heating cable systems.       Compared to conventional
                                                                                   Same application techniques as       plasters, Veneer Plaster Systems
                                                                                   for conventional plaster.            are more subject to beading
                                                                                                                        (ridging) and cracking at the
                                                                                   Greater crack resistance than        joints under rapid drying condi-
                                                                                   one-coat systems.                    tions such as those caused by
                                                                                   Can be applied directly to           low humidity, high temperature
                                                                                   concrete block.                      and/or high draft exposure.
                                                                                                                        All provide a base over which
                                                                                 Limitations                            paints or other finishes should
                                                                                   Not recommended for exterior         be applied.
                                                                                   use or where subject to weath-
                                                                                                                        Do not use a polyethylene
                                                                                   ering, direct water contact or
                                                                                                                        vapor retarder unless structure
                                                                                   temperature exceeding 125˚F
                                                                                                                        is ventilated adequately during
                                                                                   (52˚C) for extended periods of
                                                                                                                        application of veneer plasters.
                                                                                                                        A bonding agent must be
                                                                                   Framing spacing is limited and
                                                                                                                        applied to monolithic
                                                                                   partition heights are reduced in
Description                              Features/Benefits                                                              concrete prior to application of
                                                                                   comparison with some standard
                                                                                                                        either system.
Veneer Plaster Systems consist of a      The advantages of veneer plaster          constructions.
4' wide gypsum plastering base           over other commonly used partition                                             Do not sand finished plaster.
                                                                                   Provides less rigidity than simi-
with a special, highly absorptive        and ceiling systems include:              lar standard plaster
paper surface that is covered with         Rapid installation which reduces        systems.                            PRODUCT SHELF LIFE
thinly troweled, special purpose           overall construction time.                                                                          Storage/
                                                                                   When Uni-Kal/X-KALibur will be      Product                Shelf Life
plasters. Two basic types of veneer
                                           Appearance and surface of               applied, do not install Kal-Kore
plaster are available: Uni-Kal and                                                                                     X-KALibur               12 months
                                           conventional plaster at lower           too far in advance of plastering
X-KALibur, which are one-coat                                                                                          Kal-Kore Basecoat       12 months
                                           cost than regular plastering.           since Uni-Kal/X-KALibur bond
plaster system products; and Kal-                                                                                      Uni-Kal                 12 months
                                                                                   can be adversely affected if face
Kote, a two-coat plaster system.           High resistance to cracking,                                                Kal-Kote Smooth         12 months
                                                                                   of Kal-Kore has become faded
The gypsum plaster base, Kal-Kore,         nail-popping, impact and                                                    Kal-Kote Texture        12 months
                                                                                   from light. If Kal-Kore has been
is erected in the same manner for          abrasion failure.                       faded, apply Kal-Kote Base
both systems. Both veneer plaster
                                           Mill-mixed plaster components           Plaster or a plaster bonding
systems can be specified for virtually
                                           help assure uniform installation        agent to obtain good bond.
all types of partition and ceiling
                                           performance and finished job
constructions including wood or
steel framing or furring and masonry.
For both residential and commercial      One-Coat System
buildings, either type of veneer         Features/Benefits
plaster system produces a wall more      (Uni-Kal®/X-KALibur® BRAND)
nail-pop resistant than drywall            Requires only one plastering
and, when properly installed, more         material on the job.
crack resistant than conventional
                                           Slightly lower in-place cost than
lath and plaster.
                                           two-coat system.
                                           Can be applied directly to
                                           concrete block.
                                           X-KALibur is formulated to have
                                           extended set characteristics beyond
                                           traditional Uni-Kal setting times.

Veneer Plaster System Components

                                                                                             Size                          Thickness         Edge        Pcs./Bdl.
                                                                                             4'x8'                        3/8" (9.5 mm)     Tapered          2
                                                                                     (1219 mm x 2438 mm)
                                                                                           4'x8', 12'                    1/2" (12.7 mm)     Tapered           2
                                                                                 (1219 mm x 2438 mm, 3657 mm)            1/2" (12.7 mm)
                                                                                           4'x8', 12'                    5/8" (15.9 mm)     Tapered           2
                                                                                 (1219 mm x 2438 mm, 3657 mm)                  FSK
                                                                                           4'x8', 12'                    5/8" (15.9 mm)     Tapered           2
                                                                                 (1219 mm x 2438 mm, 3657 mm)                  FSK
                                                                                           4'x8', 12'                    5/8" (15.9 mm)     Tapered           2
                                                                                 (1219 mm x 2438 mm, 3657 mm)                  FSK

                                                                                 FASTENERS FOR ATTACHING KAL-KORE
                                                                                 Framing           Kal-Kore              Fastener             Fastener Spacing
                                                                                 Screw           1/2" (12.7 mm)        Type S Screws             12" o.c. Max.
                                                                                 Studs &                        1" (25.4 mm) for single layer      (305 mm)
                                                                                 Furring         5/8" (15.9 mm) 1-5/8" (41.3 mm) for two-ply
Kal-Kore® BRAND                        when used in tested systems as
                                                                                                  3/8" (9.5 mm)  1-1/4" (31.8 mm) annular        Ceiling 7" o.c.
                                       well as greater resistance to surface                                         or 4d box nails**          (178 mm) Max.
Kal-Kore is a tapered edge gypsum      indentation. Long edges of the            Wood            1/2" (12.7 mm) 1-1/4" (31.8 mm) annular Sidewall 8" o.c.
wallboard plastering base having a     panels are tapered to allow joints        Framing                             or 5d box nails**          (203 mm) Max.
blue absorptive face paper surface                                                               5/8" (15.9 mm) 1-3/8" (34.9 mm) annular
                                       to be reinforced and concealed                                                or 6d box nails**
designed to permit rapid trowel        with Kal-Mesh Tape and Uni-Kal
application and strong bond of         Plaster.                                 ** Alternate: On walls, 1-1/4" (31.8 mm) Type W screws are spaced 12" (305 mm) when
Kal-Kote, Uni-Kal and X-KALibur                                                   framing is 24" o.c. (610 mm), 16" (406 mm) when framing is 16" o.c. (406 mm).
plasters. Also available foil backed   Gold Bond® BRAND                          SPACING OF FRAMING OR FURRING
or Fire-Shield (Type X). Kal-Kore is   Hi-Impact® XP®
manufactured to conform to ASTM                                                  Type of                                                          Maximum
                                       5/8" Kal-Kore                             Framing or                       Kal-Kore                          Spacing
Specification C 588/C 1396 and
CSA A82.27.
                                       Fire-Shield Type X                        Furring                         Thickness                         on center
                                                                                 Wood                           3/8" (9.5 mm)                    16" (406 mm)*
                                       Hi-Impact BRAND Kal-Kore Fire-Shield                                    1/2" (12.7 mm)                   24" (610 mm)**
Gold Bond® BRAND                       Type X plaster base is a tapered                                        5/8" (15.9 mm)                    24" (610 mm)
Hi-Abuse® XP®                          edge panel consisting of a fire           Metal***                       3/8" (9.5 mm)                         N.A.
                                                                                                               1/2" (12.7 mm)                    16" (406 mm)
Kal-Kore Plaster Base                  resistive Type X gypsum core
                                                                                                               5/8" (15.9 mm)                    24" (610 mm)
                                       encased in a blue absorptive face
Hi-Abuse BRAND Kal-Kore Fire-                                                   N.A.–Not Approved.
                                       paper designed to permit rapid
Shield Type X Plaster Base panels                                                * Bound edge of Kal-Kore must be at right angles to framing for ceiling or walls.
                                       trowel application and strong bond       ** Bound edge of Kal-Kore must be at right angles to joists. 16" (406 mm) maximum
consist of a fire resistive type X
                                       of Kal-Kote, Uni-Kal and X-KALibur           spacing for bound edge of Kal-Kore parallel to joists.
gypsum core encased in a heavy,                                                 ***On ceilings, screw furring channel [7/8" (22.2 mm) depth] shall span 48" (1219 mm)
                                       plasters and strong liner paper on the
blue absorptive face paper designed                                                 maximum. Resilient furring channel [1/2" (12.7 mm) depth] shall span 24" (610 mm)
                                       back side. Lexan film is bonded to the       maximum. For greater spans, 1-5/8" (41.3 mm) Screw Studs may be used as Ceiling
to permit rapid trowel application
                                       back side of the panel to provide            Furring Channels provided they are secured with flanges up (open side up) at
and strong bond of Uni-Kal Veneer                                                   spans not to exceed: 6' (1829 mm) at 12" o.c. (305 mm) spacing, 5'6" (1676 mm)
                                       additional impact/ penetration               at 16" o.c. (406 mm) spacing and 5' (1524 mm) at 24" o.c. (610 mm) spacing.
Plaster and strong liner paper on
                                       resistance. Kal-Kore Fire-Shield Type
the back side. Hi-Abuse XP Kal-Kore
                                       X Hi-Impact XP is manufactured to
Fire-Shield Type X Plaster Base
                                       conform to ASTM specification C
features a specially formulated core
                                       588/C 1396 and Federal Specification
to provide fire resistance ratings
                                       SS-L-30D Type VI Grade X

Kal-Kote®                                Kal-Kote®                               Uni-Kal®/X-Kalibur®
Base Plaster                             Smooth Finish                           Uni-Kal and X-KALibur are single
Kal-Kote Base Plaster is a specially     Kal-Kote Smooth Finish is designed      component veneer plasters for
designed high strength basecoat          to provide a white smooth trowel        application over Gold Bond tapered
plaster for application 1/16"            finish using conventional plastering    edge 1/2" Regular or 5/8" Fire-Shield
minimum thickness over Kal-Kore,         techniques. Apply not exceeding         Kal-Kore, 5/8" Hi-Abuse Kal-Kore,
masonry or monolithic concrete           1/16" over Kal-Kote Base.               5/8" Kal-Kore Hi-Impact or as a
that has been treated with a                                                     finish coat over Kal-Kote base.
                                         Requires the addition of water
bonding agent.                                                                   When applied in a thin coat 3/32"
                                         only. It may also be used as a finish
                                                                                 thick and troweled to a smooth
Strength of Kal-Kote Base is sub-        for conventional basecoat plasters.
                                                                                 finish, they provide a durable,
stantially greater than that exhibited   Small amounts of commercial
                                                                                 abrasion-resistant surface for further
by typical sanded basecoat plaster.      retarder may be cautiously used to
                                                                                 decoration. X-KALibur has a longer
Fire Resistance                          slow the setting time when used
                                                                                 extended working time. Uni-Kal
                                         over conventional basecoat plasters.
Fire ratings equivalent to those of                                              and X-KALibur may be worked to a
drywall systems can be obtained by       Bag Weight                              variety of textured finishes.
applying the corresponding Kal-          50 lbs. (22.7 kg)                       Uni-Kal and X-KALibur applied not
Kore type and thickness over the         Coverage (est.)*                        exceeding 1/16" may be used as a
same framing member size and                                                     finish coat over a 3/32" coat of
spacing, with the same fasteners.        1/16" coat troweled on Kal-Kote
                                                                                 Kal-Kote Base Plaster for a total
The total plaster thickness should       Base Plaster, 650-700 sq. yds. per
                                                                                 minimum thickness of 1/8".
be a minimum of 1/8".The minimum         ton (145-160 sq. ft. per bag).
                                                                                 Strength of Uni-Kal and X-KALibur
1/8" thickness is achieved by
applying a finish not exceeding
                                         Kal-Kote®                               provides a surface resistant to
1/16" over 3/32" of Kal-Kote Base        Texture Finish                          abrasion, cracking and nail-pops.
Plaster.                                 Kal-Kote Texture Finish is designed     Fire Resistance
Specification Reference                  to provide a variety of decorative      Fire ratings equivalent to those of
                                         surfaces using common plastering        drywall systems can be obtained by
ASTM Designation C 587.                  techniques. Applied as a 1/16"          applying the corresponding Kal-Kore
Bag Weight                               finish coat over Kal-Kote Base. It      type and thickness over the same
                                         requires the addition of water only.    framing member size and spacing
80 lbs. (36.3 kg)
                                         Bag Weight                              with the same fasteners and 3/32"
Coverage (est.)
                                                                                 of Uni-Kal or X-KALibur.
                                         50 lbs. (22.7 kg)
1/16" on Kal-Kore Base, 425-475
                                                                                 Specification Reference
sq. yds. per ton (150-170 sq. ft. per    Coverage (est.)*
bag). One coat to level over                                                     ASTM Designation C 587.
                                         1/16" coat troweled on Kal-Kote
masonry, 225-275 sq. yds. per ton        Base Plaster, 650-700 sq. yds. per      Bag Weight
(80-100 sq. ft. per bag).                ton (145-160 sq. ft. per bag).          50 lbs. (22.7 kg)
                                                                                 Coverage (est.)*
                                                                                 3/32" on Kal-Kore Base, 600-665
                                                                                 sq. yds. per ton (135-150 sq. ft. per
                                                                                 bag). One coat to level over
                                                                                 masonry, 300-350 sq. yds. per ton
                                                                                 (70-80 sq. ft. per bag).

                                                                                 *Coverage estimates over conventional
                                                                                 plasters are approximately the same as
                                                                                 over Kal-Kore Base Board for conventional

Veneer Plaster Accessories*
Used in Both One-Coat and Two-Coat Systems

                                            KAL-KORNER BEAD                         E-Z STRIP® CONTROL JOINT
                                            Formed of galvanized steel to protect   Designed for drywall or veneer
                                            exterior corners with veneer plas-      plaster systems. A vinyl extrusion
                                            tering. Flange length 1-1/4".           used as an expansion or control
                                                                                    joint for ceilings or partitions.

                                            EXPANDED VENEER                         KAL-MESH TAPE
                                            CORNERBEAD                              A coated non-adhesive fiberglass
                                            Used as an alternate to the Kal-        tape which is stapled to Kal-Kore
                                            Korner Bead for exterior corners.       to reinforce all joints and interior
                                            Has 1-1/4" flanges.                     angles.

                                            ARCH CORNERBEAD                         1-1/2" DRYWALL FURRING
                                            Can be used straight for exterior       CHANNEL CLIP
                                            corners or flanges, or may be           Attaches screw furring channel to
                                            snipped and bent to form arches.        1-1/2" cold rolled steel channel.

                                            VENEER J TRIM CASING BEAD               .093 ZINC CONTROL JOINT
                                            Used as a finished edge at door         Designed as an expansion or con-
                                            and window jambs by slipping            trol joint for ceiling and partition
                                            over edge of plaster base.              areas for both drywall or veneer
                                                                                    plaster systems.

                                            VENEER L TRIM CASING BEAD
                                            Used as a finished edge at door
                                            and window jambs.

* Metal products are not manufactured by National Gypsum Company.


Veneer Plaster                             concrete stub nails or appropriate        frames, and other openings, unless         Three acceptable methods of
for Metal                                  fasteners through channel flanges         control joints are created using E-Z       treating Kal-Kore joints are:
and Wood Framing                           into the masonry or concrete.             Strip Control Joints.                      Drywall Paper Tape
                                           Fasteners shall be spaced on              4. Fasten Kal-Kore to framing              Treatment Method
1. Wood Studs or Joists. Wood              alternate flanges not over 24" o.c.
members shall meet the minimum                                                       members with face out, using the           1. Trowel Kal-Kote Base Plaster,
                                           Apply Kal-Kore vertically or              proper type and spacing of fasten-
requirements of local building codes.      horizontally in maximum lengths                                                      Uni-Kal or X-KALibur over joint line
Framing shall not exceed spacing                                                     ers shown under types of fasteners.        filling the channel formed by the
                                           to minimize end joints.
shown on page 14. Most partition                                                     5. Draw Kal-Kore tight to framing.         tapered edges of the Kal-Kore board
                                           4. Furred Ceilings with Bar Joists.       Drive fasteners straight and dimple        in an even fashion.
fire ratings require that Kal-Kore be
applied vertically.When such ratings       Attach regular furring channel 16" o.c.   the surface without breaking the
                                           to bar joists spaced up to 4' o.c.                                                   2. Center drywall paper tape over
are not required, horizontal applica-                                                paper face.                                the joint line and embed the tape
tion may be used to minimize joints.       Resilient Furring Channel (wire-tied
                                           only) shall span a maximum of 24".        Kal-Korner Bead Application                into the soft plaster using a trowel
For ceilings, application at right                                                                                              and level the joint. Tape the full
angles to framing is preferred.            Wire tie Furring Channel to joists or     Install Kal-Korner Bead using appro-
                                           use 1-1/2" Drywall Furring Channel        priate fasteners spaced 12" apart.         length of the joint.
2. Metal Studs. Align floor and            Clip for 1-1/2" carrying channel.Apply                                               3. Allow the treated joints to set
ceiling tracks to assure plumb parti-                                                E-Z Strip Control Joint
                                           Kal-Kore with paper bound edges at                                                   prior to general plaster application.
tion. Secure track with appropriate                                                  Application
                                           right angles to the furring channel.
fasteners at a maximum of 24" o.c.                                                   Install E-Z Strip Control Joint at 30'     Sta-Smooth Paper Tape
Position studs in track on specified       Kal-Kore Application                      max. spacing on walls and 50' max.         Treatment Method
centers by rotating into place for a       Note: Application shall conform to        spacing in either direction on ceilings.   1. Mix Sta-Smooth Compound per
friction fit. Secure studs located adja-   ASTM C 844.                               Apply the control joint with staples       instructions on package. Do not
cent to door and window frames,                                                      spaced 6" along each side of the           contaminate the compound with
partition intersections and corners by     1. Cut and position Kal-Kore accu-        flanges.                                   other materials, dirty water or pre-
self-drilling sheet metal screws           rately. Bring all joint edges together                                               vious mixes. Do not retemper.
                                           but do not force into place. Position     Treatment of Kal-Kore Joints
through both flanges of studs and                                                                                               2. Apply the Sta-Smooth
tracks or by use of screw stud clinch-     all end joints over framing members.      Pre-treat all joints and fasteners in
                                           To avoid ridging, minimize gaps           Kal-Kote and Uni-Kal Plaster Systems       Compound to the joint by hand or
ing tool. Apply Kal-Kore vertically for                                                                                         machine tool. The drywall paper
most fire ratings. When ratings are        between adjacent panels.                  with Kal-Kote Base Plaster, Uni-Kal,
                                                                                     X-KALibur or Sta-Smooth Joint              tape must be centered over the
not required, horizontal application       2. Minimize the number of end                                                        joint line and embedded into the
may be used to minimize joints.            joints by using maximum practical         Compound.
                                                                                                                                soft compound. Do not over-trowel
3. Masonry Wall Furring with               lengths with proper positioning.          Low humidity, high temperatures            to a slick surface. Leave the surface
Screw Furring Channel. Attach              3. Stagger joints so that they occur      and rapidly circulating air can            rough to provide mechanical key-
furring channel vertically spaced          on different framing members and          cause cracking of plaster and joint        ing of the plaster.
not to exceed spacing shown on             will not be directly opposite one         beading when Kal-Kore is applied
                                                                                     to metal framing. To minimize this         3. Allow the treated joints to set
page 14. Fasten each channel with          another on partitions. Avoid joining                                                 and dry prior to general plastering.
                                           Kal-Kore at corners of doors, window      during these conditions, joints may
                                                                                     be pre-treated using paper tape.

           Uni-Kal or X-KALibur Finish                              Kal-Kote Smooth Finish                                 Kal-Kote Texture Finish

                                                                          Kal-Kote Base                                         Kal-Kote Base

                   Kal-Kore Board                                        Kal-Kore Board                                         Kal-Kore Board

Kal-Mesh Treatment Method
Do not use self-adhering mesh.
1. Center and secure Kal-Mesh
over all joints and interior angles
with 1/4" or 5/16" staples.
2. Position staples a maximum of
24" apart as follows:
     A. Joints: at alternate edges for
     the run from end to end and
     directly opposite one another at
     either end.
     B. Angles: along ceiling edge
     only for wall-to-ceiling angles.
     Along one edge for wall-to-wall
3. After the first staples are placed
at the end of a joint or angle, pull
unstapled Kal-Mesh as stapling
proceeds to assure that it will lie
flat against the Kal-Kore.
4. Pre-treat all joints and Kal-Beads
with Kal-Kote, Uni-Kal or X-KALibur
Plaster. Tightly trowel over joint line
in both directions to prevent voids,
feathering to a maximum width of          during and after installations.         2. Add plaster and allow to soak       directly, or in previously prepared
about 6".                                 During cold weather, maintain a         for about 1 minute or add plaster      water solution form to obtain the
                                          temperature 55˚F (13˚C) to 70˚F         as mixer is turning, then mix until    most uniform effect.
5. Allow the treated joints to set        (21˚C) before, during and after         uniformly wetted.
prior to general plaster application.                                                                                    2. Never use gauging or moulding
                                          installation of all system components   3. Add remaining water and mix         plasters in place of commercial
                                          until building is occupied.
Plastering                                                                        sufficiently to obtain desired lump-   accelerator since they can adversely
                                          Mixing                                  free material fluidity.                affect working qualities.
Note: Application shall conform to
ASTM C 843.                               Equipment: Mixing should be             Note:
                                          done with a high-speed mechanical       A. Mixing periods greater than 5
                                                                                                                         Kal-Kote Application
The same general job conditions
                                          mixer. A paddle-type agitator fitted    minutes will not be required if
                                                                                                                         Over Kal-Kore
used in good conventional plastering                                                                                     Basecoat Over Kal-Kore
                                          to a 500-600 RPM heavy duty,            proper equipment and procedure
practice should be maintained.
                                          1/2" electric drill and a clean,        are used.                              1. Tightly scratch material into
However, because Veneer Plaster
                                          smooth-sided drum of convenient         B. Mix no more than two bags per       previously treated joints and corner-
coats are thin, particular action
                                          size are recommended for rapid,         batch to avoid mixing too far in       beads, then immediately scratch-in
must be taken to guard against
                                          efficient mixing of all Kal-Kote        advance of application.                tightly over the wall and/or ceiling
dryouts (primarily avoiding direct
                                          Plaster types.                                                                 area.
exposure to concentrated sources                                                  C. Caution is advised against mixing
of heat and drafts.)                      Water Ratios: Use only clean,           more than two successive batches       2. Double back over the area just
                                          fresh water suitable for human          without thorough equipment clean-      troweled with material from the
Special attention should also be
                                          consumption. Basecoat: 10-12 qts.       up to avoid undue set acceleration.    same batch bringing total thickness
given to temperature conditions
                                          per 80 lb. bag. Smooth Finish: 18-20                                           up to 1/16" minimum.
under which the system is installed.                                              D. Avoid the practice of mixing
                                          qts. per 50 lb. bag. Texture Finish:
Both “in-place” and application                                                   partial bags since this leads to       3. When plaster has “taken up,”
                                          11-12 qts. per 50 lb. bag. Uni-Kal
performance of individual Veneer                                                  difficulty in maintaining uniform      eliminate excessive trowel marks
                                          and X-KALibur: 13-15 qts. per
System components will be greatly                                                 material qualities.                    and fill all surface voids and imper-
                                          50 lb. bag.
enhanced if all construction areas                                                                                       fections to obtain a reasonably
                                          Procedure                               Job Setting Adjustment
and materials are at a suitable                                                                                          uniform surface. Do not over-trowel
temperature equilibrium before,           1. Put all but 1 to 2 qts. of the       1. Basecoat and Finish Plasters:       to a slick surface. Roughen the
                                          proper water volume in a suitable       Small amounts of commercial            unset basecoat plaster surface with
                                          mixing drum.                            retarder or commercial gypsum          a serrated darby or lightly wire rake
                                                                                  type accelerator may be cautiously     to provide mechanical keying for
                                          Note: Starting with an insufficient     used to adjust setting time when       the finish plaster when necessary.
                                          amount of mixing water will seriously   extreme conditions demand. When
                                          degrade mixing and application          commercial retarder or accelerator
                                          performance.                            is used, add to mixing water

Smooth Finish Over Basecoat              2. Double back over the area just        Veneer Plasters Direct                  3. When plaster has “taken up”,
1. Apply only over properly prepared     troweled with material from the          to Bond-Coated                          eliminate excessive trowel marks
Kal-Kote basecoat plaster. Scratch-in    same batch bringing total thickness      Monolithic Concrete                     and fill all surface voids and imper-
tightly, then double back with           up to 3/32" minimum.                                                             fections to obtain a reasonably
                                                                                  Description                             uniform surface. Do not trowel to a
material from the same batch             3. Begin finish troweling at time
immediately to create a uniform          of initial set, using water sparingly.   The Kal-Kote System, consisting of      slick surface. Roughen the unset
coat not exceeding 1/16" in average      Final troweling must be accom-           a basecoat plaster and a finish         basecoat plaster surface with a
thickness.                               plished before complete set takes        coat plaster, Uni-Kal or X-KALibur      serrated darby or lightly wire rake
                                         place, as evidenced by darkening         may be applied directly to mono-        to provide mechanical keying for
2. Remove trowel marks, “cat faces,”                                                                                      the finish plaster when necessary.
                                         of the surface.                          lithic concrete treated with a bond-
and other major surface imperfec-
                                                                                  ing agent.                              Smooth or Textured Finishes
tions by “drawing-up” or “laying         Note: Uni-Kal or X-KALibur may
down” the surface with light trowel      be applied to produce a textured         Limitations                             Apply finishes to the Kal-Kote
pressure when plaster has stiffened.     finish.                                  1. Surface to be plastered shall be     Plaster as outlined under the regular
Use water sparingly if needed, but       A. When Uni-Kal or X-KALibur is          treated with a bonding agent            Kal-Kote System as described on
do not over-trowel or over-water         mixed, add up to but not exceed-         applied according to manufacturer’s     page 18.
because this aggravates any normal       ing 50 lbs. of silica sand, texturing    directions. The performance of this
tendency for blistering when working     grade, per 50 lb. bag of plaster.        system is the sole responsibility of    Uni-Kal or X-KALibur
over low suction bases. Such                                                      the bonding agent manufacturer.         Application over
                                         B. The sanded Uni-Kal or X-KALibur                                               Bonding Agent
blistering will be eliminated by the     mix should be scratched-in tightly       2. Concrete should be aged at
final water-troweling operations.        over the plastering base. Immediately    least one month prior to plastering.    1. First straighten any major surface
3. Water-trowel to densify and polish    double back over the area just                                                   irregularities such as holes, ridges,
                                                                                  3. Kal-Kote Smooth or Texture
the surface to the desired degree        troweled with material from the                                                  wavy sections, etc. Scratch plaster
                                                                                  Finishes are not designed for direct
when plaster has set, eliminating        same batch.                                                                      in tightly by trowel and fill out to
                                                                                  application to concrete, but must
any blistering if present. Never use                                                                                      any adjacent level area.
                                         C. When plaster is well taken up,        first have Kal-Kote Base Plaster
a felt “blister brush” as a substitute   float to the desired texture finish.     applied to fill and level surface.      2. Allow the straightening material
for water troweling!                                                                                                      to set.
                                         Painting Plaster                         4. Do not apply system to the
4. Uni-Kal and X-KALibur Plaster                                                  interior side of exterior walls below   3. Tightly scratch material in over
may be substituted for Kal-Kote          Various job conditions such as           grade. To use above grade these         the wall and/or ceiling area. This
Smooth Finish.                           suction differences, wet or only         walls shall be kept dry and shall       application should be about 1/16"
                                         partially dry walls, and reactions       have been properly waterproofed         thick. Double back over the area
Texture Finish Over Basecoat             between paint and lime may               on the exterior side to prevent         just troweled with material from
1. Apply per (1) under Smooth            cause unsatisfactory paint finishes                                              the same batch bringing total
                                                                                  water penetration.
Finish.                                  particularly on new construction.                                                thickness up to 3/32" minimum.
                                                                                  Application Procedures
2. When plaster has stiffened, float     Alkali-resistant primers specifically                                            4. Begin finish troweling at time of
its surface to any desired finish.       formulated for use over new plas-        Note: Application shall conform to
                                                                                                                          initial set, using water sparingly.
                                         ter will permit decorating with oil      ASTM C 843.
Do not float the soft surface                                                                                             Final troweling must be accom-
of plaster which has already set.        or latex type paints. Quality paint                                              plished before complete set takes
                                         products should be used and              Kal-Kote Base
Up to equal parts of clean, graded                                                Application Over                        place, as evidenced by
                                         manufacturers’ recommendations                                                   darkening of the surface.
silica sand may be added to Uni-         followed. Finished plaster should        Bonding Agent
Kal and X-KALibur to aid texturing.      be painted or covered to conceal                                                 Veneer Plasters Direct
                                                                                  1. First straighten any major sur-
Uni-Kal or X-KALibur                     possible discoloration. The paint        face irregularities, such as holes,     to Unit Masonry
                                         system should be suitable for            ridges, wavy sections, etc. Scratch
Application                              use over plaster surfaces that           plaster in tightly by trowel and fill
over Kal-Kore                            contain lime.                            out to any adjacent level area.         The Kal-Kote System, consisting of
1. Tightly scratch material into                                                                                          a basecoat plaster and a finish
                                         It is essential that plaster be sound    2. After the straightening material
previously treated joints and corner-                                                                                     coat plaster, Uni-Kal or X-KALibur,
                                         and completely dry before painting.      has set, trowel in a tight scratch
beads, then immediately scratch-in                                                                                        and the one-coat system, may be
                                         Under good drying conditions,            coat over the entire area to be
tightly over the wall and/or ceiling                                                                                      applied direct to masonry surfaces
                                         veneer plaster may be painted 48         plastered; then immediately double
area.                                                                                                                     providing the following recommen-
                                         hours after application.                 back with material from the same        dations are followed.
                                                                                  batch to minimum thickness of
                                                                                  1/16" or as required to achieve a
                                                                                  level surface. Use a rod or feather
                                                                                  edge if needed.

Recommendations                           Veneer Systems                           Application Procedures                   2. Apply Kal-Kore to the flanges of
1. Surface must be free from dirt,        Applied to Masonry                       1. Begin application of Z Furring        Z Channel with 1" Type S screws
grease, oil, mold, parting agents, or     with Z Furring                           members by positioning first channel     spaced 12" o.c. Normally, vertical
                                                                                                                            application of Kal-Kore is recom-
any material which will prevent           Channel System                           vertically at a corner, locating it on
                                                                                                                            mended; however, for installations
plaster adhesion.                                                                  the wall adjacent to the wall being
                                          Description                                                                       8' or less in height, horizontal
2. When erecting masonry, strike                                                   insulated first.
                                          This system consists of a Z Furring                                               application may be preferred since
joints flush. If masonry has                                                       The insulation thickness determines      the number of joints would be
                                          Channel, rigid insulation and the
recessed joints, fill joints flush to                                              the distance of Z Furring web from       reduced.
                                          components of the Kal-Kote and
masonry surface with basecoat                                                      wall being insulated. At the appro-
                                          Uni-Kal or X-KALibur Veneer                                                       3. Apply Kal-Mesh and Kal-Korner
plaster, Uni-Kal or X-KALibur and                                                  priate distance, with wide flange
                                          Plaster Systems. The Z Furring                                                    Bead according to procedures
allow to set.                                                                      pointing toward applicator, secure Z
                                          Channel is manufactured from                                                      described on pages 16 and 17.
Exterior Corners                                                                   Channel with appropriate fasteners,
                                          galvanized steel (.0179" min. base
                                                                                   spaced 24" o.c. driven through           4. Mix and trowel on Kal-Kote
Install cornerbead with adhesive at       steel) and is produced with web
                                                                                   short flange. (Note: Power-driven        Base and Finish Plaster or Uni-Kal
least 4 and preferably 16 hours           depths of 1", 1-1/2" and 2". The
                                                                                   fasteners are not recommended for        Plaster as described on pages 18
before plastering.Apply a continuous      furring channel which is applied to
                                                                                   use with masonry block.)                 and 19.
bead of adhesive approximately 1/4"       a masonry wall holds the insulation
x 1/4" along the inside of both           in place and the wide flange serves      Install 24" wide floor-to-ceiling
cornerbead flanges. Press the bead        as framing for the application of        insulation panel, pressed snugly
firmly over the corner so that            the Kal-Kore plastering base.            against web of first Z. Install next Z
adhesive is in continuous contact                                                  with the wide flange overlapping
with masonry surface. Align bead                                                   the edge of the first insulation
                                          1. Since the interior wall surface       panel. Fasten Z to wall through
and allow to stand undisturbed
                                          will take the general configuration      narrow flange. Continue in this
at least 4 hours.
                                          of the masonry wall, it may be nec-      manner with Z Furring member
Kal-Kote Application                      essary when applying the system          24" o.c. to end of wall. Locate last
Note: Application shall conform to        to unit masonry to use portland          Z so that web is located a distance
ASTM C 843.                               cement plaster to bring the wall to      equal to insulation thickness from
                                          a plane surface.                         adjoining wall. Cut last insulation
Proceed with the full field of the wall
                                          2. This system is mainly for new         panel to fit remaining space.
by scratching-in tightly, then double
back immediately with material from       masonry construction. On well-cured      At exterior corner, attach the Z
the same batch to a minimum thick-        concrete or masonry, it may be           through its wide flange with narrow
ness of 1/16" over the block surface,     difficult to properly drive fasteners.   flange extending beyond the corner.
or as required to level.                  3. Power-driven fasteners shall          Begin with a narrow strip of floor-
                                          be used only for attachment to           to-ceiling insulation, wider than
Kal-Kote Finishes should be kept as
                                          monolithic concrete surfaces.            insulation thickness, but not
thin as possible and applied as
                                                                                   exceeding 3". Continue application
described on pages 18 and 19.             4. Kal-Kore should be applied within     of furring and insulation progres-
Uni-Kal or X-KALibur                      24 hours of foam application.            sively as described above.
                                                                                   At windows, doors and trim areas,
Caution: Since Uni-Kal or X-KALibur                                                use wood nailers, nominal 2" wide
is a one-coat material system,                                                     x insulation thickness plus 1/32".
exercise care in leveling the wall to                                              Use the nailers also at wall-floor
compensate for the uneven suction.                                                 angles to support trim and provide
Proceed with full field of the wall                                                backing for base.
by scratching-in tightly, then double
back immediately with same batch
of material to a minimum thickness
of 3/32" over the block surface.

Veneer Plaster Problems and Solutions

Conditions/Causes/                      The prime job conditions initiating         Improper or deficient substrate          Structural and framing
Prevention/Correction                   problems are:                               for accepting plasters.                  irregularities and deficiencies.
Veneer plaster problems are gener-         Improper material storage and         Some of the problems associated             Fastening deficiencies.
ally related to job conditions or          handling.                             with veneer plaster construction            Structural movement.
abuses and marginal or improper            Poor or improper plastering           have the same cause - prevention –
                                                                                 correction characteristics as drywall.   Attention to good plastering
plastering techniques or practices         practices and techniques.                                                      practices and procedures will
and infrequently to a product quality                                            These main common conditions are:
                                           Adverse or extreme environmental                                               minimize or eliminate job site
deficiency.                                conditions.                              Gypsum base application               problems and call-backs.

Condition                               Probable Cause                           Preventive Action                        Corrective Action
Joint Cracking                          1. Wrong type of reinforcing mesh        1–3. Use proper type of mesh and         Large Cracks: Scrape crack
                                           or tape was used.                        recommended joint installation        and apply drywall tape and setting
                                        2. No reinforcing mesh was used, or         procedures. – DO NOT USE SELF-        type joint compound.
                                           improperly positioned over joint.        STICK (PRESSURE SENSITIVE) MESH.      Small Cracks: Fill and feather
                                        3. Joint not pretreated prior to         4. Avoid hot, low humidity air, high     out area with ready mixed joint
                                           general plastering.                      draft exposure.                       compound.
                                        4. Rapid drying conditions.              5. Install control joints as required.
                                        5. Expansion/contraction.                6. Avoid extreme and rapid tempera-
                                        6. Thermal shock.                           ture differentials (thermal shock).
                                        7. Structural movement.                  7. Avoid jointing plaster base at
                                                                                    corners of openings, stagger joints
                                                                                    on opposite side of partition.

Random Or Map Cracking                  Concentrated stresses caused by          Maintain minimum 55°F (18°C)             Fill and feather area with ready
                                        differential shrinkage or expansion      conditions prior to, during and after    mixed joint compound.
                                        between plaster and substrate or         plastering.
                                        between individual plaster coats –
                                        thermal shock.

Mud Cracking                            Rapid drying or too thin plaster         Avoid rapid drying conditions, apply     Apply ready mixed joint
(Craze, Shrinkage, Alligator)           application.                             plaster at recommended thickness.        compound.

Dryout                                  1. Rapid drying conditions.              1. Avoid rapid drying conditions.        General or large area “dry-outs” –
                                        2. Thin plaster application.             2. Apply plaster at recommended          remove plaster; vacuum or wipe
                                        3. Excessive job addition or retarder.      thickness.                            down surface, apply bonding agent
                                                                                 3. Avoid job additions of retarder.      and replaster.
                                                                                                                          Small areas – spray surface with
                                                                                                                          water or alum solution to set plas-
                                                                                                                          ter. Repair area with ready mixed
                                                                                                                          joint compound for an acceptable

Nail Pops                               1. Nail or screw heads                   Follow recommended veneer plaster        Remove plaster around fastener
                                           puncturing face paper.                base application procedures.             and seat it properly and drive an
                                        2. Nails or screws not securely                                                   additional fastener about 1-1/2"
                                           driven, loose or improper type.                                                away from the popped fastener.
                                        3. Framing members out of align-                                                  Patch with plaster or ready mixed
                                           ment or lumber shrinkage.                                                      joint compound.
                                        4. Plaster base not applied tight
                                           against framing members.

Condition                                Probable Cause                            Preventive Action                        Corrective Action
Joint Ridging Or Beading                 1. Large gaps between adjacent            1–3. Apply undamaged plaster             Sand the ridge or bead and apply
     Most commonly occurring                plaster base boards.                      base board according to               ready mixed compound and feather
     when steel studs (24" on center)    2. Improper/insufficient number/             recommended procedures using          out areas.
     are used and rapid drying              location of fasteners.                    proper fastening.
     conditions exist                    3. Gypsum base board edges damaged.       4/5. Use recommended
                                         4. Wrong type or no reinforcing              reinforcing mesh or paper tape
                                            mesh used.                                and pretreat joints prior to gen-
                                         5. Joints not pre-treated prior to           eral plastering.
                                            general plastering.                    6. Avoid rapid drying conditions.
                                         6. Rapid drying conditions.

Rusting/Staining Of Finish               Use of improper fasteners or metal        Use only recommended fasteners           Prime affected area with a primer/
                                         trim.                                     and trim.                                sealer and redecorate.

Photographing Or Ghosting                1. Differential in base plaster suction   Apply basecoat plaster to full           Prime affected area with a primer/
Of Joint Line                               between joint and field.               thickness, following recommended         sealer and redecorate.
                                         2. Too thin a coat of base plaster        procedures.
                                            overall, resulting in a very thin
                                            covering over mesh.
                                         3. Partially dry base plaster, moisture
                                            content differential greater
                                            between joint and field.

Joint Shadowing Caused By                Gypsum veneer base gapped                 Follow recommended veneer base           Fill depression with joint compound or
Depression Or Ridging                    causing a depression or ridge at          and plaster application procedures.      sand ridges flush with field, skim coat
                                         the joint line.                                                                    with joint compound and redecorate.

Bond Failure                             Product Related Causes:                   The best advice for preventing           Remove all loose or marginally
     Cause(s) of bond failure is         1. Use of pressure sensitive mesh –       veneer plaster problems is to strictly   bonded plaster, brush the surface
     perhaps the most difficult con-        reduces plaster substrate contact.     follow the manufacturer’s recom-         thoroughly to remove dust (vacu-
     dition to diagnose because of       2. “Setting” or “drying” type joint       mendations and adhere to proper          uming is recommended), apply a
     the great number of factors which      compounds used to treat joints.        plastering practices.                    quality bonding agent per manu-
     can influence plaster bonding       Job Condition Causes:                                                              facturer’s recommendations and
                                         1. “Dry-out” or “partial dry-out” –                                                replaster.
                                            plaster loses water prior to com-
                                            plete setting or hydration.
                                         2. Using plaster which has been
                                            exposed to the atmosphere,
                                            open bags or improper storage.
                                         3. Freezing of plaster before setting
                                            has occurred.
                                         4. Application of plaster over frost
                                            on substrate.
                                         5. Excessively rapid thermal changes.
                                         6. Excessive thermal differences
                                            between the face and back of
                                            the plaster base.
                                         Application Practice Causes:
                                         1. Application of lime containing plas-
                                            ter over light faded veneer base.
                                         2. Use of retempered plaster,
                                            remixing with additional water
                                            plaster which has “bucked-up”
                                            (stiffened) or started to set to
                                            render it workable again.
                                         3. Excessive delay in applying plaster
                                            after mixing – application near
                                            or into the initial setting action.

Condition                     Probable Cause                               Preventive Action                        Corrective Action
Bond Failure (cont.)          4. Excessive use of retarder to slow         The best advice for preventing           Remove all loose or marginally
                                 setting, so partial dry-out occurs.       veneer plaster problems is to strictly   bonded plaster, brush the surface
                              5. Adulteration of the plaster on the        follow the manufacturer’s recom-         thoroughly to remove dust (vacu-
                                 job site by addition of substances        mendations and adhere to                 uming is recommended), apply a
                                 other than clean graded silica            proper plastering practices.             quality bonding agent per manu-
                                 sand or excessive use of sand.                                                     facturer’s recommendations and
                              6. Application of plaster over                                                        replaster.
                                 improper substrate.
                              7. Application of plaster over
                                 contaminated substrate, dust,
                                 dirt, oil, soot, etc.
                              8. Application of plaster over
                                 substrate with excessively high
                                 suction – too high absorptivity.
                              9. Application of plaster over sub-
                                 strate with inadequate absorp-
                                 tivity – too low suction.
                              10. “Laying-on” or “buttering-on”
                                 plaster without adequate trowel
                                 pressure to provide mechanical
                                 keying to the substrate.
                              11. Inadequate or insufficient fin-
                                 ish troweling.
                              12. Basecoat plaster troweled too
                                 smooth – reduces mechanical
                                 keying of finish to the base plaster.
                              13. Finish plaster applied over base-
                                 coat plaster too thick, and not tightly
                                 troweled into the base plaster.
                              14. One coat finish applied too thin.
Hard (Set) Lumps In Package   Plaster bags became wet                      Protect plaster from water               1. Screen out hard lumps before
                              during transit or storage.                   during transit and storage.                 mixing.
                                                                                                                    2. Discard the plaster.

Set Time Variable Within      1. Improper mixing equipment.                1. Use recommended mixing                See Prevention.
The Same Job Mixed Batch      2. Insufficient water used at the               equipment.
                                 start of mixing.                          2. Add all but about 1 quart of the
                              3. Insufficient mixing time.                    recommended amount of water
                                                                              to the mixer at start.
                                                                           3. Mix to a uniform fluidity; mixing
                                                                              time should not exceed 5 minutes.

Set Time Variable From        1. Dirty equipment                           1. Use only clean equipment.             See Prevention.
Batch To Batch                2. No or improper equipment                  2. Follow recommended equip-
                                 clean-out procedures.                        ment clean-out procedures.
                              3. Partial bag mixed.                        3. Use only full bags.

Slow Set Plaster              1. Temperature below 40°F (4°C)              1. Avoid extremes of air, plaster        1/2. During cold weather maintain
                                 or in excess of 100°F (38°C).                and mix water temperature.               temperature between 55° and
                              2. Job addition of retarder.                 2. Avoid job addition of retarder.          70°F before, during and after
                              3. Use of old, improperly stored             3. Use only properly stored plaster         plastering. Avoid job additions of
                                 plaster or plaster from open bags            from unopened bags, less than            retarder. Cautiously use accelera-
                                 which have been exposed to air.              a year old.                              tor to speed up setting action.
                              4. Partial bag mixed.                        4. Use only full bags.                   3. Replace material.
                                                                                                                    4. Use only full bags.

Condition                             Probable Cause                           Preventive Action                        Corrective Action
Quick Set                             1. Dirty equipment.                      1. Follow recommended clean-out          1–5. Follow good recommended
                                      2. Excessive mixing.                        procedures.                              plastering practices.
                                      3. Contaminated mixing water.            2. Do not exceed 5 minutes mixing        6. Cautiously use retarder to slow
                                      4. Plaster has become wet or                time.                                    set time.
                                         contaminated prior to mixing.         3. Use only potable water.               7. Use only full bag.
                                      5. Excessive use of accelerator.         4. Use only properly stored, uncon-
                                      6. Excessively low air/plaster mix,         taminated plaster.
                                         water temperatures below 40°F         5. Maintain construction areas and
                                         (4°C).                                   materials above 55˚F prior to,
                                      7. Partial bag mixed.                       during and after plastering.
                                                                               6. Avoid job additions of accelerator.
                                                                               7. Use only full bag.

Spreading Qualities                   1. Improper mixing equipment/            Use recommended mixing equip-            See Prevention.
Vary Within Batch                        mixing action.                        ment, water ratio and procedure.
                                      2. Insufficient water used at start of
                                      3. Insufficient mixing time.
                                      4. Aggregate separation.

Spreading Qualities Vary              1. Inconsistent mixing.                  1. Follow recommended mixing             See Prevention.
From Batch To Batch                   2. Using part or open bags exposed          procedures.
                                         to air.                               2/3. Use only full, unopened bags,
                                      3. Old or improperly stored plaster.        which have been properly stored.
                                      4. Variable aggregate.                   4. Replace aggregate and/or plaster.

Smooth Or Texture Finish              1. Surface of unset plaster being        1. Adjust finishing sequence to          See Prevention.
Desired, Not Obtained                    worked at wrong time, too stiff          meet plaster condition.
                                         or too soft.                          2. Gypsum Base: Adjust plaster
                                      2. Suction of substrate too high or         working time sequence to com-
                                         too low.                                 pensate for high or low suction.
                                      3. Surface of plaster being worked          Basecoat Plaster: Apply finish
                                         after plaster has set.                   over “green” moderately dry
                                      4. Intermixing material from different      basecoat or dampen dry basecoat.
                                         manufacturers.                        3. Follow recommended smooth or
                                                                                  texturing procedures.
                                                                               4. Use only materials from single
                                                                                  producer to ensure compatibility.

Blistering Of Smooth Finish           1. Application of water onto the         1. Reduce trowel pressure during         Eliminate blisters with strong
     A common condition, especially      plaster surface with troweling           “double-back” and “draw-up”           trowel pressure during final water
     over “green” basecoat plaster,      before sufficient stiffening             operation. Use water sparingly        troweling operation, when plaster
     less over gypsum veneer base        (“take-up”) has occurred.                and only after adequate plaster       is firm and/or setting action in
                                      2. Aggravated by cold plastering            “take-up” has developed or ini-       progress.
                                         surfaces.                                tial setting action has occurred.
                                                                               2. Maintain recommended working
                                                                                  area temperature.

Fuzzing Or Ragging Of                 1. Finish plaster surface lacks          1. Wet trowel or sparingly apply         See Prevention.
Smooth Finish Surface                    sufficient water for adequate            water on plaster surface during
                                         trowel lubrication or slip during        “draw-up”.Avoid starting “draw-
                                         “draw-up” operation.                     up” too long after “take-up”.
                                      2. Job-gauged finish components          2. Be sure job-gauged finish
                                         not uniformly blended, causing           components are uniformly and
                                         localized dry spots due to               thoroughly blended.
                                         uneven water retention.               3. Decrease trowel angle to surface,
                                      3. Excessive trowel pressure, trowel        ease up on trowel pressure or
                                         at wrong angle to the surface or         start troweling sequence sooner.
                                         timing wrong for troweling.
Condition                               Probable Cause                          Preventive Action                        Corrective Action
Peeling And Tearing Of Smooth           1. “Double-back” coat of finish         1. “Scratch” and “double-back”           See Prevention.
Finish During Application                  troweled over “scratch” coat            with finish from the same batch,
                                           which has stiffened excessively         minimizing time between coats.
                                           or set.                              2. Use only light, even trowel
                                        2. Trowel pressure during “draw-           pressure when “drawing-up”.
                                           up” too strong for stiffness and
                                           thickness of finish.
Paint Peeling/Blisters                  1. Plaster not completely dry.          1. Allow sufficient drying time
  Use only quality paints               2. Wrong type of paint used.               before painting; consideration to     1/2. Remove all peeling/blistering
  specifically recommended by           3. Plaster surface chalky.                 environmental conditions is              paint, allow sufficient drying
  the paint manufacturer for            4. Plaster surface contaminated,           imperative.                              time. Prime and redecorate.
  application over lime                    grease, soot.                        2. Use only paint specifically rec-      3. Remove all peeling paint,
  (alkaline) containing plasters        5. Plaster became wet after                ommended by the paint manu-              and brush surface to remove
                                           decoration was completed.               facturer for use over new or             chalkiness. Apply primer recom-
                                                                                   freshly plastered surfaces.              mended by paint manufacturer
                                                                                3. Finish plaster per recommended           for chalky plaster surfaces.
                                                                                   practices, leave plaster surface
                                                                                   under trowel, do not brush finish.
                                                                                4. Examine plaster surface for signs
                                                                                   of contamination prior to painting.
                                                                                5. Make sure areas are weather tight
                                                                                   before plastering and printing.

Joint Shadowing                         Depression or ridge at the joint        See “Joint Shadowing Caused By           See “Joint Shadowing Caused By
                                        line.                                   Depression Or Ridging.”                  Depression Or Ridging.”

Paint “Stringing” or “Roping”           1. Wrong type of paint.                 1. Use proper type of paint for          1. Stop painting.
During Roll Application                 2. Solids content of paint too high.       plaster surfaces.                     2. Check preventative measures
                                        3. Fast drying conditions.              2. Dilute paint per manufacturer’s          and make necessary corrections.
                                        4. Plaster surface dusty.                  recommendations.                      3. Allow painted area to dry and
                                                                                3. Reduce drying conditions.                repair by either sanding the
                                                                                4. Make sure plaster is dust free.          affected area or skimming with
                                                                                                                            joint compound to a smooth
                                                                                                                            surface and repaint.
                                                                                                                         4. Brush the surface thoroughly
                                                                                                                            to remove dust (vacuuming is

Painting Plaster
Various job conditions such as suction differences, wet or only partially dry
walls, and reactions between paint and lime may cause unsatisfactory
paint finishes particularly on new construction.
Alkali-resistant primers specifically formulated for use over new plaster
will permit decorating with oil or latex type paints. Quality paint products
should be used and manufacturers’ recommendations followed. Finished
plaster should be painted or covered to conceal possible discoloration.
The paint system should be suitable for use over plaster surfaces that
contain lime.
It is essential that plaster be sound and completely dry before painting.
Under good drying conditions, veneer plaster may be painted 48 hours
after application.

Glossary of Terms
Accelerator . . . . . . . . . . . . . . . . . . . .A substance used to shorten or speed up the setting action (time) of the plaster.
Admixture . . . . . . . . . . . . . . . . . . . .A substance other than water, or aggregate added to the plaster to alter its properties.
Aggregate . . . . . . . . . . . . . . . . . . . .An inert material used as a filler or texturing aid.
Anhydrite . . . . . . . . . . . . . . . . . . . . .An anhydrous form of gypsum.
Basecoat . . . . . . . . . . . . . . . . . . . . . .A plaster coat applied over a substrate prior to application of the finish coat.
Blistering . . . . . . . . . . . . . . . . . . . . .Bulging or separation of the wet finish plaster coat away from the base.
Bond . . . . . . . . . . . . . . . . . . . . . . . . .Adhesion between plaster coats or between plaster and substrate produced by mechanical and
                                               chemical properties of the plaster, or intermediate bonding agents applied prior to plastering.
Bonding Agent . . . . . . . . . . . . . . . .An adhesive substance applied to a substrate to provide a medium for plaster bond.
Brown Out . . . . . . . . . . . . . . . . . . . .A darkening of the exposed plaster surface indicating setting action is complete.
Buck-Up . . . . . . . . . . . . . . . . . . . . . . .A premature stiffening of plaster mortar shortly after mixing. Usually indicates a plaster deficiency
                                               or an adverse reaction to a job addition of aggregate.
Calcine . . . . . . . . . . . . . . . . . . . . . . . .To drive off water of crystallization by heating.
Calcined Gypsum . . . . . . . . . . . . . .Gypsum with 1-1/2 molecules of combined water removed – also called plaster, stucco, hemihydrate, semihydrate.
Cat Face . . . . . . . . . . . . . . . . . . . . . .A blemish or rough depression in the finish coat plaster.
Chemical Bond . . . . . . . . . . . . . . . . .Bond produced by the formation and subsequent interlocking of gypsum crystals during the setting process.
Coat . . . . . . . . . . . . . . . . . . . . . . . . . .A thickness, covering, or layer of plaster applied in a single operation.
Consistency . . . . . . . . . . . . . . . . . . .An amount of water required to bring a unit weight of dry plaster to a workable fluidity.
Craze Cracks . . . . . . . . . . . . . . . . . . .Fine random fissures or cracks in the plaster surface caused by plaster shrinkage due to loss of water before setting.
Cure . . . . . . . . . . . . . . . . . . . . . . . . . .The state of or conditions conducive to complete hydration of the plaster.
Dolomite . . . . . . . . . . . . . . . . . . . . . .A type of lime or limestone containing calcium with up to 50% magnesium as the hydroxide or carbonate.
Double-Up . . . . . . . . . . . . . . . . . . . .Plaster placement characterized by application of material from the same mixed batch in successive
                                               operations without setting or drying allowed between coats – double-back, laid-off, or two-coat work.
Draw-Up . . . . . . . . . . . . . . . . . . . . . .The troweling process after the applied finish plaster has “taken up”, whereby surface irregularities are filled
                                               and leveled with or without the use of fresh plaster on the tools.
Dry-Out . . . . . . . . . . . . . . . . . . . . . . .A condition where some or all of the water necessary for plaster hydration is lost by evaporation or excessive suction.
Efflorescence . . . . . . . . . . . . . . . . . .A white, fleecy surface deposit of salts.
Fat . . . . . . . . . . . . . . . . . . . . . . . . . . .Soft usable plaster accumulated on trowel during finishing operation, often used to fill in small imperfections.
Finish Coat . . . . . . . . . . . . . . . . . . . .The last layer of plaster applied – smooth or texture.
Finishing Brushes . . . . . . . . . . . . . .Brushes used to dash water onto the surface of finish plaster during smooth troweling.
Float . . . . . . . . . . . . . . . . . . . . . . . . . .Tool or procedure used to straighten and level the finish coat surface to correct surface irregularities
                                               produced by other tools and to impart a distinctive surface texture.
Float Finish . . . . . . . . . . . . . . . . . . . .A finish coat texture derived primarily from aggregate particles in the plaster.
Gauging . . . . . . . . . . . . . . . . . . . . . .Gypsum plaster added to lime putty to provide and control set.
Green . . . . . . . . . . . . . . . . . . . . . . . . .Newly applied plaster that has set but not completely dried out.
Hawk . . . . . . . . . . . . . . . . . . . . . . . . .Tool used by plasterers to hold and carry plaster mortar, in conjunction with troweling.
Hemihydrate . . . . . . . . . . . . . . . . . .Calcined gypsum.
High Calcium Lime . . . . . . . . . . . . .The oxide or hydroxide derived from limestone, which is principally calcium carbonate.
                                               The product contains less than 5% magnesium oxide or hydroxide.
Hydrate . . . . . . . . . . . . . . . . . . . . . . .Term used to denote hydrated lime.
Hydrated Lime . . . . . . . . . . . . . . . . .Quicklime (oxide) which has been hydrated to yield the hydroxide, a dry powder.
Joining . . . . . . . . . . . . . . . . . . . . . . . .The juncture of two separate plaster applications on a common surface.
Landplaster . . . . . . . . . . . . . . . . . . .Ground natural gypsum.
Lay Down . . . . . . . . . . . . . . . . . . . . .The troweling process after the applied finish plaster has “taken up”, whereby surface irregularities are filled
                                               and leveled with or without the use of fresh plaster on the tools.

Lean Mixture . . . . . . . . . . . . . . . . . .High aggregate to plaster ratio; often exhibits poor working qualities.
Light Weight Aggregate . . . . . . . .Expanded perlite or vermiculite.
Lime . . . . . . . . . . . . . . . . . . . . . . . . . .Oxides or hydroxides of calcium or calcium and magnesium.
Lime Putty . . . . . . . . . . . . . . . . . . . .A thick paste obtained by “slaking” quicklime or soaking and mixing hydrated lime with a minimum of water.
Mechanical Bond . . . . . . . . . . . . . .Physical keying of plaster to substrate.
Mill Mixed . . . . . . . . . . . . . . . . . . . .Plasters requiring only water addition on the job site.
Mortar . . . . . . . . . . . . . . . . . . . . . . . .A material used in plastic state which can be troweled and hardens after placement.
Mud Cracks . . . . . . . . . . . . . . . . . . . .Fine random cracks in the plaster surface caused by plaster shrinkage due to loss of water (dry-out) before setting.
Perlite . . . . . . . . . . . . . . . . . . . . . . . .A siliceous volcanic glass – expanded by heating into a lightweight plaster aggregate.
Plaster Bond . . . . . . . . . . . . . . . . . .Adhesion between plaster coats or between plaster and a plaster substrate produced by a mechanical
                                            and chemical interlocking of plaster with the substrate.
Purity . . . . . . . . . . . . . . . . . . . . . . . . .The percentage of calcium sulfate dihydrate contained in a fully hydrated gypsum plaster.
Relative Humidity . . . . . . . . . . . . . .The ratio of the amount of water vapor actually present in the air to the greatest amount possible
                                            at the same temperature, expressed as a percentage.
Retarder . . . . . . . . . . . . . . . . . . . . . .A material added to plaster which will lengthen the setting time.
Retemper . . . . . . . . . . . . . . . . . . . . .To mix additional water with plaster which has begun to stiffen or set so as to render it workable again.
Sand . . . . . . . . . . . . . . . . . . . . . . . . . .A washed and size-graded, granular natural material (aggregate) added to veneer plasters to aid float
                                            texturing of the plaster.
Scratch And Double . . . . . . . . . . . .Plaster application characterized by a tight application of plaster against the substrate and immediately
                                            followed by a second application of plaster from the same batch of mixed plaster.
Setting Time . . . . . . . . . . . . . . . . . . .The elapsed time after mixing with water for the plaster to harden or hydrate.
Sweeten . . . . . . . . . . . . . . . . . . . . . .The troweling process after the applied finish plaster has “taken up”, whereby surface irregularities are filled
                                            and leveled with or without the use of fresh plaster on the tools.
Take-Up . . . . . . . . . . . . . . . . . . . . . . .A normal stiffening of the applied plaster resulting from the removal of water from the plaster by absorption
                                            (suction) into the substrate.
Trowel Finish . . . . . . . . . . . . . . . . . .Denotes a smooth finish surface produced by troweling.
Veneer Plaster . . . . . . . . . . . . . . . . .A specially manufactured gypsum plaster which provides strength, hardness and abrasion resistance and
                                            is capable of thin application over designated substances.
Veneer Plaster Base . . . . . . . . . . . .A gypsum board with special paper facing designed to provide water absorption for rapid veneer plaster
                                            application and finishing.
Workability . . . . . . . . . . . . . . . . . . . .The ease and speed with which plaster mortar can be applied and finished.

CUSTOMER SERVICE SALES AREAS                                  Technical Data          LIMITED WARRANTY
                                                                                      AND REMEDIES
                                                                                      Products manufactured and sold by
                                                                                      National Gypsum are warranted by National
                                                                                      Gypsum to its customers to be free from
                                                                                      defects in materials and workmanship at
                                                                                      the time of shipment. THIS EXPRESS
                                                                                      WARRANTY IS THE ONLY WARRANTY
                                                                                      APPLICABLE TO SUCH PRODUCTS, AND IS
                                                                                      IN LIEU OF AND EXCLUDES ALL OTHER
                                                                                      EXPRESS ORAL OR WRITTEN WARRANTIES
                                                                                      AND ALL IMPLIED WARRANTIES, INCLUDING
                                                                                      BUT NOT LIMITED TO THE IMPLIED
                                                                                      WARRANTIES OF MERCHANTABILITY AND
                                                                                      FITNESS FOR A PARTICULAR PURPOSE.
                                                                                      National Gypsum will not be liable for any
                                                                                      incidental, indirect or consequential losses,
                                                                                      damages or expenses. The customer’s
                                                                                      exclusive remedy for any type of claim or
                                                                                      action for defective products will be limited
                                                                                      to the replacement of the products (in the
                                                                                      form originally shipped) or, at National
                                                                                      Gypsum’s option, to a payment or credit
                                                                                      not greater than the original purchase
                                                                                      price of the products.
                                                                                      National Gypsum will not be liable for
                                                                                      products claimed to be defective where the
                                                                                      defect resulted from causes not within
                                                                                      National Gypsum’s control, or which arose
  Atlantic Area                       Northeast Area          National Accounts       or occurred after shipment, including but
                                                                                      not limited to accidents, misuse, mishandling,
  Phone: (800) 237-9167               Phone: (800) 253-3161   Phone: (800) 440-1230   improper installation, contamination or
  Fax: (877) 252-0430                 Fax: (866) 632-1480     Fax: (866) 622-3590     adulteration by other materials or goods,
  Central Area                        Southeast Area          Manufactured Housing    or abnormal conditions of temperature,
                                                                                      moisture, dirt or corrosive matter.
  Phone: (800) 252-1065               Phone: (800) 548-9394   Phone: (800) 455-3185
                                                                                      Any claim that products sold by National
  Fax: (866) 232-0440                 Fax: (866) 732-1990     Fax: (800) 639-1714     Gypsum were defective or otherwise did
  Gulf Area                           Southwest Area                                  not conform to the contract of sale is
                                                                                      waived unless the customer submits it in
  Phone: (800) 343-4893               Phone: (800) 548-9396                           writing to National Gypsum within thirty
  Fax: (866) 482-8940                 Fax: (866) 792-7520                             (30) days from the date the customer
  Midwest Area                        Western Area                                    discovered or should have discovered the
                                                                                      defect or nonconformance. No legal action
  Phone: (800) 323-1447               Phone: (800) 824-4227                           or proceeding complaining of goods sold
  Fax: (866) 692-8590                 Fax: (800) 438-6266                             by National Gypsum may be brought by the
                                                                                      customer more than one year after the
                                                                                      date the customer discovered or should
                                                                                      have discovered the defect or problem of
                                                                                      which it complains.

Corporate Headquarters              Technical Information
National Gypsum Company             Phone: (800) NATIONAL
2001 Rexford Road                          (800) 628-4662
Charlotte, NC 28211                 Fax: (800) FAX-NGC1
Phone: (704) 365-7300                      (800) 329-6421

                                                                                                             110753       Rev. 5/07

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