Laying & Maintenance of Terrazzo


Characteristics of Terrazzo

Terra-stone Terrazzo, will darken randomly from moisture absorbed when newly laid or after rain in outdoor areas, but will return to a uniform, lighter colour in time, once dry, depending on weather conditions and exposure to sunlight.

1.Adequate Curing of Concrete Slabs and Screeds Prior to Tiling

New concrete slabs or screeds upon which Terra-Stone tiles are to be laid must be adequately cured to prevent the transfer of any substrate shrinkage cracks. The concrete slab must be at least 6 weeks old and any screeds must be at least 4 weeks old before being tiled.

2a. General Laying Specifications

Before laying the tiles, the surface bed must be dampened. If there is any dust residue on the back of the tiles wash this area with a block brush and water. Lay tiles on a clean stable concrete or masonry substrate, using a non-marking rubber mallet to ensure tiles are laid evenly with the least lippage possible, using a quality guaranteed 12 hour set tile adhesive. Use Terra-Stone Tile Adhesive guaranteed for our Terrazzo tiles (porcelain fast set tile adhesives are not to be used). Ensure each tile is fully bedded and supported throughout, with at least 95% tile adhesive coverage. A 12mm notched trowel must be used to spread the adhesive on the floor and also a thin layer of adhesive must be applied to the entire underside of the tile by back buttering with adhesive. To do this, place the tile upside down on a 20 litre bucket, for ease of application of the adhesive, apply the adhesive on the entire underside of the tile using the flat edge of the adhesive trowel. The tiles must then be installed by firmly bedding them by standing on the tiles and thereafter, using a tiler’s mallet, to ensure there is no lippage from one tile to the next. Lay tiles with a 5-8mm joint for the 600mm format. Tiles to be laid in a grid format. Grouting provides support to the tiles after laying and prevents water ingress. Grouting should take place between 24 and 48 hours after laying. For walls composed of wood or dry walling, a suitable paste tile adhesive must be used.

Ensure all excess tile adhesive and grout is always thoroughly wiped off the tile surface with a damp sponge as the tiling progresses.

2b.Tiling of External Areas And on Suspended floor Slabs

In external areas the concrete slab must have a sheet of waterproofing plastic beneath the concrete floor slab, to prevent rising damp or moisture. On suspended concrete slabs and externally in outdoor areas, use the guaranteed Terra-Stone Adhesive, with 50% bond replacement, of all the mixing water. A 50% bond replacement of all mixing water for grout is also essential to ensure the surface of the floor is properly sealed to prevent any water ingress. In outdoor areas, ensure the substrate and tiles are laid to a fall away from the building, to allow quick drainage and prevent pooling of rainwater, which could cause problems later. Cover the tiles with a sheet of plastic immediately after laying. Leave the plastic sheet in place for 24 hours to protect against inclement weather and to ensure proper curing for a good and solid bond.

Follow laying instructions as per paragraph 2a. above.

3.Grouting of Classic Polished, Lava Stone and Rustico Textured Tiles

Ensure after completing the tiling or grouting procedure, the tiles are left clean each day, wiping them clean with a damp sponge as the grouting progresses every 1-2m2. No tile adhesive or grout is to remain on the face of the tiles for more than half an hour prior to cleaning. UFT grey quarry grout is the recommended flooring grout.

4.Expansion Joints

Allow movement joints against the perimeter walls of the area being tiled and on floors every 4,5LM or where there are existing construction or expansion joints in the substrate. On suspended floor slabs, expansion joints must be provided every 3LM. Flexible joint fillers must have no oil content, as the oil is absorbed into the tile, leaving unsightly dark edges.  An acrylic silicone is recommended with no oil content.  Where tiles are laid in a staggered bond system, this system should only be used internally, due to thermal stresses in the external environment and be sure to provide expansion joints in both directions.

5.Tile Protection During Tiling and Construction

In a construction environment, cover the newly laid tiles with plastic or non-marking boarding until final handover, to avoid damage and soiling by following trades. Ensure red clay soil is not left on the tiles during construction, as the fine clay particles may permeate the surface and stain the tiles.

Any sawdust allowed to get wet on the tile surface, must be avoided, as it may leach out natural wood tannin, which could stain the Terrazzo tiles.

6.Sealing Procedure of the Tile


Once laid and grouted, a “single coat” of UFT Concrete & Stone Sealer for the Rustico and Lava Stone ranges is to be applied, using a lamb’s wool roller.  Ensure surface is clean and dry before sealing. (Warning: – more than one coat makes the surface slippery)!


Two thin even coats of UFT Concrete & Stone Sealer are to be applied on the Classic Polished and Mediterranean Handcrafted patterned ranges with a clean micro fibre mop or pad applicator, available from Union Tiles, to ensure ease of maintenance, for both the tile and grouted areas after installation. Tile surface is to be clean and dry prior to sealing. Allow the first coat to dry (±15min) before applying the second coat. Thereafter, for high traffic areas, such as restaurants, mall walkways and shops etc., apply one thin coat of UFT Dresser, (a water based buffable and sacrificial surface sealer) on a clean dry tile surface and ensure to use a clean micro fibre mop or pad applicator, to apply the dresser, available from Union Tiles. (See procedure detailed below.)

7. General Maintenance


On the Classic Polished, Mediterranean and Rustico ranges: for high traffic areas, such as restaurants and shopping malls, UFT Dresser is a “maintenance and sacrificial top dresser coat” and is to be applied only very occasionally, in isolated areas, where the sealants are showing signs of wear, however, it is essential that the surfaces are cleaned immediately prior to application, of any dresser coats. Where there are signs of wear of the existing sealer, UFT Dresser will provide a buffable, protective coating filling any minor sealer surface scratches, further enhancing the gloss finish, and prolonging the life of the sealants beneath and improving the stain resistance of the tile.

The UFT Dresser can also be easily stripped away by applying UFT Stripper during the cleaning process, should the dresser coating tarnish over time (±2-4 years). (UFT Stripper will strip the dresser, but not the protective sealer beneath).  Indoor areas need not be resealed again, provided the top maintenance dresser coats are adequately maintained, depending on exposure to direct sunlight, and the extent of foot traffic in the area.


Only neutral soap detergents should be used to clean and maintain the Terra-Stone tiles on a regular basis. ‘’SQT Natural Stone Detergent’’ is the recommended cleaning and very effective degreasing neutral soap for these tiles.  Best cleaning results are in combination with a solution of SQT Natural Stone Detergent in warm water and a red 3M pad attached to a mechanical scrubber, and then the dirty cleaning water is to be removed with a wet and dry vacuum.  All cleaning machinery, sealers and soaps are available from Union Tiles.


A one-year product guarantee is supplied on our Terra-Stone Tiles provided all instructions and maintenance procedures are adhered to. The guarantee is strictly limited to the value of the Terrazzo tile product supplied and invoiced and does not include any consequential or inconsequential damages for, labour, materials or other costs.


Acid based cleaners, thinners, strong ammonia cleaning chemicals and acetone should never be used on the tiles. Acid cleaning chemicals will corrode the surface of the tiles, while ammonia and acetone will damage the protective sealant. Red clay soil must not be left on the tiles during construction, as the fine clay particles will penetrate and stain the tile. Paint spillages should be avoided by covering the tiles with drop sheets. Do not mix the tile batches in one area, always keep different batches in separate areas.

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