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The laying of terrazzo flooring can be carried out by two methods, namely, In-situ laying and precast terrazzo tiles laying. The terrazzo flooring laid using precast terrazzo tiles flooring, its specifications, and laying procedure is discussed below.
The In-situ terrazzo flooring is discussed in the article- How to Lay In Situ Terrazzo (Marble Chips) Flooring? [PDF]
Terrazzo Tiles Specification
- The tiles shall be initially grinded and grouted for wearing layers.
- The size of the tiles shall be as given in table-1 below.
- The tolerance in the size of the tiles shall be ± 1mm.
- The tolerance in thickness shall be +5mm.
- The terrazzo tiles shall be manufactured under pressure processes subjected to hydraulic pressure of not less than 140 kg per square centimeter.
- The top surface of the tile must be free from projections, depressions, cracks, holes, cavities, and other blemishes.
- Where coloring material is used in the wearing layer, it shall not exceed 10 percent by weight of cement used in the mix.
- The finished thickness of the upper layer of the terrazzo tile shall not be less than 5 mm for the size of marble chips from the smallest up to 6 mm and the same wise 5 mm for marble chips, smallest to 12mm, and 6mm for marble chips smallest to 20mm.
Table 1: Sizes of Terrazzo Flooring Tiles.
|Length in mm||Breadth in mm||Thickness in mm|
|200 mm||200 mm||20 mm|
|250 mm||250 mm||22 mm|
|300 mm||300 mm||25 mm|
Procedure of Laying Terrazzo Tile Flooring
1. Laying of Terrazzo Tiles
- The base concrete on which the tiles are to be laid shall be cleaned, wetted, and mopped.
- The bedding for laying of tiles shall be cement mortar of the following specification-
1. 1:2 (1 part of cement: 2 part of course sand)
2. 1:3 (1 part of cement: 3 part of course sand)
3. 1:4 (1 part of cement: 4 part of course sand)
- The ingredients shall be thoroughly mixed by volume in dry form, which shall be free form hard lumps.
- The thickness of the bedding mortar shall be 30 mm, and the thickness at any place shall not be less than 10 mm.
- The cement mortar shall be spread, tamped, and corrected to proper levels, and the tiles shall be laid immediately after laying of mortar.
- A grey cement slurry of honey-like consistency shall be spread at the rate of 4.4 kg of cement per square meter over the bedding.
- The tiles which are to be laid shall be washed clean and shall be fixed in this grout one by one, each tile being gently tapped with a wooden or rubber hammer till it is properly bedded in the mortar, and is in level with the adjoining/ adjacent tiles.
- The joints of the tiles shall be kept as thin as possible, not exceeding 1.5 mm.
- The tiles are laid in straight lines or in a way to suit the desired pattern.
- The surface of the flooring shall be checked frequently with a straight edge at least 2 meters long, to obtain a true surface with the required slope.
- At the places where full tiles or half tiles can not be fixed, tiles shall be cut (sawn) from full tiles to the required size, and their edges rubbed smooth to ensure a straight and true joint.
- Once the tiles have been laid, surplus cement grout that may have come out of the joints shall be cleared off.
2. Curing, Polishing and Finishing of Terrazzo Tiles Flooring
- The day after the terrazzo tiles are laid, all joints shall be cleaned off with grey cement grout with a wire brush to a depth of 5 mm, and all dust and loose mortar removed and cleaned.
- The joints shall then be grouted with grey or white cement mixed with or without pigment to match the shape of the topping of the wearing layer of the tiles.
- The same cement slurry shall be applied to the entire surface of the tiles in a thin coat in order to protect the surface from abrasive damage and fill the pinholes that may exist on the surface.
- The floor after laying shall then be kept wet for a minimum period of 7 days to cure.
- The surface shall thereafter be grounded evenly with a machine fitted with coarse grade grit block (No.60) while water shall be used profusely during grinding.
- After grinding, the surface shall be thoroughly washed to remove all grinding mud, cleaned, mopped, and covered with a thin coat of grey or white cement in order to fill any pinhole that may appear.
- The second grinding shall then be carried out with a machine fitted with fine grade grit block (No. 120).
- The final grinding with a machine fitted with the finest grade grit blocks (No.320) shall be carried out the day after the second grinding before handing over the floor.
- For small areas where machine polishing is not feasible, hand polishing shall be permitted. The hand polishing shall be carried out with the use of following carborundum stones-
1. 1st Grinding- Coarse grade stone (No. 60)
2. 2nd Grinding- Coarse grade stone (No. 80)
3. 3rd Grinding- Coarse grade stone (No. 120)
- After the final polish is completed, oxalic acid shall be spread over the polished surface (33 gm per square meter) followed by sprinkling of water and rubbed hard with a pad or woolen rugs.
- The following day of acid wash, the floor shall be wiped with a moist rug, dried with a soft cloth, and finished clean.
FAQs on Terrazzo Tiles Flooring
Terrazzo flooring is estimated to last up to 75 to 100 years with proper maintenance and care.
The tolerance in the size of terrazzo tiles is -
Tolerance in length and width - ± 1mm.
Tolerance in thickness - 5mm
The thickness of the bedding mortar for laying terrazzo tile flooring shall be 30 mm, and the thickness at any place shall not be less than 10 mm.
The joints of the terrazzo tiles flooring shall be kept as thin as possible, not exceeding 1.5 mm, and are laid in straight lines or in a way to suit the desired pattern.
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