Masonry Contractors Estimates by zau21261


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									                Maintain       production     history      files   on every    masonry         task

                                                By Carolyn Schierhorn

E     xperiencedcontractorsrarely
      have trouble estimating ma-
                                        work for productivity," observes
                                        Dan Schiffer of Holt, Mich.-based
                                                                                estimated into discrete, measur-
                                                                                able tasks," Schiffer explains. "So
                                                                                if we look at plans for a block
      terial quantities neededfor a     Schiffer Mason Contractors Inc.,
job, but estimating labor hours         who has developed masonry esti-         wall requiring #5 rebar at 2 feet,
can be a lot trickier. A multitude      mating software and teaches             8 incheson center,grouted cells,
of factors affect productivity, from    classes on estimating. For exam-        control joints, anchor bolts at the
unit size, shape,and weight to          pIe, a contractor may know that         top, and sawcuts, as well as the
weather conditions.What's more,         a mason can lay 200 standard            units themselves,we have a pro-
 all masonry tasks must be accu-        lightweight block a day but have        ductivity number for eachtask-
 rately measured,including the in-      no idea how many lineal feet of         so many lineal feet, cubic feet, or
 stallation of flashing, anchorbolts,   sawcuts a mason can make.               units per day."
 movementjoints, and insulation.           "In our company, we break               Schifferconvertsproductionfig-
    "So many peopleuse guess-           down everything that needs to be        ures into "man-day" units, which

Figure 1. Concrete masonry production curve                  Figure 2. Face brick production    curve
                                                                                                    accurately, maintain meticulous
               Table 1. Special block production                         factors                    production history records, up-
                                                                                                    dating your counts weekly.
                                                         Basic     Production
                                                                                                    William Pacetti, president of
 Special block                Size           Weight   production      factor          block         Pacetti Brothers and Trademen's
                                                                                                    Software in Tinley Park, Ill., pro-
 Scored                  4x8x16                 26       163           .95             155          vides his foremen with produc-
                         6x8x16                 32       150           .95             143          tion charts that include a sketch
                         8x8x16                 39       131           .95             125
                         10x8x16                47       105           .95             100
                                                                                                    of each masonry component on
                         12x8x16                54       90            .95             86           the job. At the end of each day (or
                                                                                                    week), the foremen count all the
 Slump                       4x4x16             13       191           .92             176
                             8x4x16             20       176           .92             162          installed components, turning in
                                                                                                I   the       completed   production   charts

 Split face              4x4x16                 16       184           .89             164
                         4x8x16                 33       148           .89             132          weekly.

                         8x4x16                 23       170           .89             152             Schiffer'sforemen are given
                         8x8x16                 46       107           .89             96           forms that showthe estimated
                         10x8x16                55       88            .89             79
                                                                                                    averageman-daysfor each task.
 Sound block                 4x8x16             18       180           .80             144
                             6x8x16             22       172           .80             138
                             8x8x16             27       161           .80             129

 Source:    Ref.   1, page    192

equal the number of units or ma-                         based on how soon he has to fin-
sonry accessories, or amount of                          ish thejob, he calculates the num-
material, a mason will lay on a                          ber of masons and laborers need-
project-divided by the average                           ed to complete the job on time.
number or amount he could in-                            From this figure, he determines
stall in a day if he did nothing                         his labor costs.
else.                                                       Likewise, Larry Wendt, presi-
   For example, let's say a proj-                        dent of Benchmark Estimating
ect requires 60,000 brick; 5,000                         Software in Lombard, Ill., tells
block; 1,000 cubic feet of grout;                        contractors at his estimating
and 120 anchor bolts. And the av-                        seminars to determine separately
erage daily production counts per                        the labor required for the instal-
mason are: 600 brick; 180 block;                         lation of various masonry acces-           "At the end of each day, when
200 cubic feet of grout; and 400                         sories and for tasks such as ma-           the foreman does his counts, he
anchor bolts. These figures yield                        sonry cleaning. But, he notes, few         knows how many man-days
60,000+600=100 man-days for                              masonry contractors estimate               ahead or behind he is." Then, if
bricklaying; 5,000+180=27.7 man-                         production this way.                       necessary, the foreman can en-
days for blocklaying; 1,000+200=5                           For example, to cover the cost          courage his crew to work harder .
man-days for grout placement;                            of installing flashing when done           If the crew falls way behind,
and 120+400=0.3 man-days for                            by the masons, some contractors             Schiffer might replace it with one
anchor bolt installation.                               just increase the price of the ma-          better-suited to the particular
   Schiffer sums up the total man-                       sonry units to be set on the flash-        project.
days a project requires. Then,                          ing. Others charge a flat rate,                "Many masonry contractors
                                                         such as $1 per lineal foot, for all        don't know where they stand on
      Table 2. Jointing                                 flashing. These methods, accord-            a job," Schiffer says. "We know
     method loss factors                                ing to Wendt, don't distinguish             daily on every job whether we've
                                                        between different types offlash-            made or lost money."
 Jointing     method                Lost time (%)       ing such as copper vs. plastic,                The masonry estimating soft-
                                                         and don't take changing job con-           ware packages developed by Schif-
 Flush cut (add)                       2 toS            ditions into consideration.                 fer, Pacetti, and Wendt allow pro-
 Concave                                  O
 Weathered                             O to 1
                                                            "You're comparing apples to or-         duction figures for every type of
 Struck                                O to 2           anges this way ," says Schiffer .           task to be updated easily.
 Raked                                 2to     S        "By converting every task into                 However, to estimate a job that
 V-tooled                              2to     S
                                                                                                    includes tasks or materials with
                                        Sto 8
                                                        man-days instead, you compare
 Convex                                8 to 12
                                                        apples to apples."                          which he has no experience, Schif-
                                                                                                    fer must make an educated guess
 Source: Ref. 2, page VII-6                             Know where you stand on a job               based upon history records for
                                                          To estimate future production             similar situations. If he wins the
                                                                                                          centage range of time typically
                       What influences       production?                                                  lost; subtracting this range from
   At his estimating seminars, Larry Wendt, president of Benchmark Esti-                                   100% yields the production factor
 mating Software in Lombard, Ill., emphasizes that many factors affect ma-                                for the particular task, special
 son productivity, including:                                                                             unit, or condition (Ref. 2).
 .Crew availability: Some crews may be faster than others                                                     Table 2 shows lost time due to
 .Experience of foreman                                                                                   type of jointing method. Concave
 .Expected crew size: Too many masons may get in each other's way                                         joints entail 0% lost time, which
 .Masonry unit type: With brick, look closely at initial rate of absorption,                              means a 100% production factor
    texture (affects cleaning), and voids; with block, look at unit weight, the                           for that task. Convex joints, in
    presence ofhand-holds, and special shapes                                                              contrast, result in 8% to 12% lost
 .Type of mortar                                                                                           time, or a production factor of
 .Weather conditions: Temperature, humidity, wind speed                                                    92% to 88%.
 .Current economic conditions: During good times, when there is plenty of                                     The impact of the percentage
    work, production rates go down; rates go up when there are a lot of out-of-                            of saw cut units on lost time is
    work masons                                                                                            shown in Table 3. Note that if 0%
 .Job type: Whether industrial, commercial, institutional, residential, or                                 to 5% of the units in a wall are
    publicly funded                                                                                        cuts, lost time will range from 3%
 .Overtime work: Production rates go down with overtime                                                    to 5%. If 40% to 50% of the units
 .Scheduling issues: Material availability, whether project is fast-track                                  are cuts, lost time will amount to
 .Location: Crowded site conditions, site accessibility                                                    35% to 40%.
                                                                                                               Pope breaks the production
                                                                                                           rates down into man-day produc-
job, one of his first priorities is to    to 52 pounds decreases produc-
                                                                                                           tion averages for special wall re-
do a time study. He'll go out to the      tion from 137 to 92 units. Figure
                                                                                                           inforcing, grout, loose-fill insula-
 site with a stopwatchand time a          2 shows a sample face brick pro-
                                                                                                           tion, different types of concrete
masondoing a particular task.             duction curve. The average ma-
                                                                                                           block, glazed brick, face brick,
    But if the masonlays 30 blocks        son can lay 560 5.3-pound brick
                                                                                                           and stonework, and clay and con-
in an hour, for example,Schiffer          in a day but only 29112.5-pound
                                                                                                           crete pavers. His average esti-
won't multiply that number by 8           units, according Kolkoski's graph.
                                                                                                           mates for concrete block cell fills
 hours to get a daily production               These production curves are
                                          based on standard units. Any de-                                 (grout), for instance, are: for 4-
 rate. During that hour, the ma-
                                          parture from the norm adds a                                     inch block, 55 cell fills per day; 6-
 sontook no breaks and was on
                                          degree of difficulty to the task,                                inch block, 160 per day; 8-inch
 his best behavior. Multiplying 30
                                          which can be converted into a                                    block, 180 per day; 10-inch block,
 by 6.5 hours yields a more accu-
                                          production factor. Table 1 shows                                  190 per day; and 12-inch block,
 rate estimate, Schiffer says.
                                          production factors for special                                    200 per day.
Reference charts can guide                                                                                     Estimating production can be
                                          block, including scored, slump,
                                          split-face, and sound-dampening                                   daunting because there are thou-
   When your own records are in-
                                          units. Less than 1, the produc-                                   sands of masonry unit types and
complete, you can refer to tables
                                          tion factor is multiplied by the                                  accessories and myriad outside
and graphs in masonry estimat-
ing books, which are based on the         basic production estimate for the                                 factors that can have an impact.
                                           same-weight standard unit to                                     But reducing each task to man-
authors' field experience and re-
search. These are no substitute           yield the production rate for spe-                                day units makes estimating easy,
                                           cial block.                                                      Schiffer contends. Just make
for experience but can serve as
guides until you establish com-                Similarly, Jerry Pope, author                                sure to count accurately every
                                           of Masonry Estimating for a Prof-                                component of a masonry job at
plete production history files.
   Because unit weight has a sig-                                                                           least weekly and update your
                                           it, presents production efficiency
                                           loss factors for a variety of condi-                             production history files. n
nificant impact on productivity,
Rynold V. Kolkoski, author of              tions that impair productivity,                                References
Masonry Estimating, has created            such as laying brick over the wall;                            1. Aynold V. Kolkoski, Masonry Estimating,
                                           the number of cuts in the wall;                                1988, The Aberdeen Group, 426 S. West-
graphs relating unit weight to
                                                                                                          gate St., Addison, IL 60101.
production rate (Ref. 1). Figure 1         stop-work delays; coffee break
                                                                                                          2. Jerry Pope, Masonry Estimating for a
shows a sample concrete block              delays; weather conditions; mate-                              Profit, 1993, Mason Contractors Associa-
production curve. Note that in-            rial finishes; and raking and                                  tion of America, 1550 Spring Ad., Oak
creasing the unit weight from 37           pointing. Pope estimates the per-                              Brook, IL 60521.

                                                    Reprinted    from   Masonry   Construction
                                                                 @ copyrighted    by

                                                   The          Aberdeen                         Group@

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