TERRACOTTA ♦ Defined as molded clay units, decorative or plain, whose properties are similar to those of burned bricks. ♦ The clay from which they are formed should be:- ~ Dense Burning. ~ Contains no soluble Salts. ~ Should have low shrinkage. ~ Freedom from warp age. →Test of quality for ceramic veneer and terracotta is its tone when struck, which should be bell-like. Colour:- ~ Unglazed ceramic veneer and terracotta are – Dull Ocher or Red. ~ Can vary according to the composition and temperature of firing. ~ Terracotta is used with various colour glazes, unlimited possibilities with colour on terracotta shapes for caps, bases, decorative bands, ornaments and design elements in general. FINISHES FOR TERRACOTTA Smooth Finish:- ~ Plane surface, as formed by the die in manufacturing. Ceramic Glaze:- ~ A compounded, transparent, hard coating fused to the terracotta. Non Lustrous Glaze:- ~ Surface covered by a fire bonded ceramic glaze with satin or matte finish. Ceramic Colour Glaze:- ~ Surface coating of bonded ceramic glaze either solid or mottled (two or more colours evenly distributed & somewhat blended with a satin or gloss finish). Polychrome finish:- ~ Two or more colours applied separately to specific areas and brunt separately for each colour. MANUFACTURING OF TERRACOTTA ♦ Manufactured by clay (having sufficient percentage of iron oxide 5% to 8% & lime about 1%). ♦ Mixed with large quantities of sand and pottery. ♦ Clay free from grit, organic matter, pebbles etc. ♦ Mixture ground to fine powder & pegged thoroughly. ♦ Put into molds of desired size, shape & the molds are dried for a few days. ♦ Then the articles of terracotta are taken out & further dried in a shed. ♦ Dried products are brunt in special muffle furnaces these are also known as Refectories. USES OF TERRACOTTA ♦ It has its way in construction industries like in Renovation, Authentic Restoration, for New Construction. ♦ Ceramic Veneer & Terracotta Panels used for Ornamental use in Grilles, Facades, Architectural Design & Construction work and as Screens. APPLICATION OF TERRACOTTA ♦ Applied to brick, Concrete, Concrete Block & Stone Walls in same manner as in brick, structural clay facing tile and stone by anchoring the terracotta to the wall surface. ♦ All terracotta pieces & the surface should be soaked in water for at least one hour before installation. ♦♦ Mortar should be applied on both surfaces on terracotta and wall. ♦ Terracotta should be anchored and tapped into the place. ♦ Lastly the mortar should he struck flush. → Mortar used should consist of 1 par of Portland Cement by volume, 0.5 part of High Lime Putty, 0.5 part Clean Sand, 1quart of Ammonium Serrate or its equivalent. → Cleaning should be done with the help of brushes & clean water or a weak solution of muriatic acid followed by a thorough rinsing with clear water. Condition Favorable to the Use of Ceramic Veneer & Terracotta ~ Large units are a design Consideration. ~ Where a wide choice of colour & design is required. ~ Where surface is likely to receive rough treatment. ~Where maintenance to be kept is minimum. ~Where a special surface design is desired. ~ Where fire resistance is required. ~ it should not be used as an structural material. ~ Where a sound insulation is required. ADVANTAGES OF TERRACOTTA ~ It has good strength & durability. ~ It is available in various colours. ~ It is cheaper than finely dressed stone. ~ Easy to clean. ~ Molded to any shapes. ~ It is fire proof and quite light. ~ It resist acids, gases & the atmosphere. DISADVANTAGES During drying & burning, it is likely to be distorted due to unequal shrinkage. USES Hollow blocks of terracotta used for facing work, cornices, arches, casting of columns etc. TERRA COTTA HOLLOW BLOCKS The words terra cotta mean ‘earth burned.’ .After burning,the clay has a smooth hard surface which does not readily absorb water.The blocks are made hollow so that they will be light in weight and the smooth faces of the blocks indented with grooves during moulding,to give a good key for plaster and concrete.This type of floor has to be given temporary support with timber or steel centering. The terra cotta blocks and the reinforcement are set out on the centering and pieces of clay are placed underneath the reinforcing bars.Concrete is then placed and compacted between the terra cotta blocks and spread 50thick over the top oh the blocks. This type of floor can span up to 5.0 and the depth of the blocks,the depth of the finished floor and the size and number of reinforcing bars depend on the superimposed loads and span.This type of floor is much less used today than it was because of the considerable labour in placing the hollow terra cotta pots and reinforcement and because of the need for temporary centering. These blocks also used for walling or in the form of slabs for applied internal and external wall finishs, Square terracotta tiles Square terracotta tiles Colour: red / orange Colour: red / orange 6 1/2" x 6 1/2" 6 1/2" x 6 1/2" Hexagonal terracotta tiles Hexagonal terracotta tile 7 1/2" x 7 1/2" 6 1/2" x 6 1/2" Reclaimed Antique Terra Cotta Tile 6" x 12" 4' x 4" and 5" x 5" These reclaimed Antique terracotta floor tile are distinguished by their texture, variation and the patina that comes from years of use. No new terracotta tile can compare with the relaxed informal charm of a genuine antique terracotta floor.
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