GENERAL SPECIFICATION FOR FIXING NATURAL STONE (LIMESTONE, QUARTZITE, SANDSTONE OR SLATE) TILES ONTO INTERIOR RENDERED WALLS, AND ONTO INTERIOR SURFACE BEDS AND SUSPENDED SLABS (PAGE 3)

GENERAL SPECIFICATION FOR FIXING NATURAL STONE TILES ONTO INTERIOR SURFACE BEDS AND SUSPENDED SLABS (CONTINUED)

 

•  
• ADHESIVE SYSTEM
  • Surface Beds
    • Apply  TAL GOLDSTAR 6 rapid-setting adhesive to the background using a notched trowel.
  • Suspended Slabs
    • Apply  TAL GOLDSTAR 6 rapid-setting adhesive mixed 20kg with 5 litres of TAL BOND (replacing the water in the mix) to the background using a notched trowel.
      Alternatively,  TAL BOND POWDER may be added to the adhesive mixing water at a ratio of 1 x 1kg sachet per 20kg TAL GOLDSTAR 6, or  TAL GOLDFLEX single-part flexible rapidsetting adhesive may be used. When using  TAL GOLDFLEX no additives are required, simply mix with clean water, alleviating possible mixing errors on site.
  • General:
    • In this tiling situation it is imperative that there is a solid bed of adhesive at least  6mm thick beneath each tile.  We would recommend the use of a notched  FLOOR TROWEL.
    • At no time spread more adhesive than can be tiled onto in 10 – 15 minutes. Depending on atmospheric conditions, this will normally be around 1 square metre. This prevents the adhesive from drying or “skinning” before the tiles are applied.
    • Bed dry tiles (do not soak) firmly into the wet adhesive with a twisting action to ensure full contact between the background, tiles and adhesive. Tiles should be well tapped home with a rubber mallet or the wooden handle of a trowel. It is sound practice to remove the occasional tile to ensure that good contact has been achieved.
    • When using heavily lugged tiles, or tiles with a very irregular back profile, it is good practice to butter the back of each tile, ensuring that the grooves or dovetails are completely filled with adhesive.
    • Clean off any surplus adhesive remaining on the face of tiles and between the joints with a damp sponge before the adhesive dries.
    • Never butt joint tiles. Joints are required to allow the individual tiles to move with respect to each other and thus avoid a compressive stress build-up. They are also required as vents for the tile adhesive to cure. The joints between these tiles must be a minimum of 5mm wide, or as per manufacturer’s instructions.
    • Pot life of the adhesive will vary with climatic conditions. Under no circumstances should adhesive which has been left standing for too long be reconstituted by adding more liquid.
    • Do not tile over structural, expansion or cold joints in the background. These joints must be extended through the various layers to the surface.

 

• GROUTING
  NOTE : We recommend that the face of porous tiles be sealed before grouting to minimise the risk of the grout staining the tiles. This will also minimise water penetration into the installation.
  • Grouting must not be carried out until sufficient bond has developed between the bedding mix and the tiles to preclude disturbance of the tiles during the grouting operation. Allow a minimum of 4 hours before grouting.
  • Surface Beds:
    • Option 1:  TAL Quarrygrout
      • Use grey or coloured  TAL QUARRYGROUT for filling tile joints 5mm and wider  TAL   QUARRYGROUT  is suitable for use in joints up to 25mm wide.
    • Option 2:  TAL Stain Free Grout
      • Use Light Grey  TAL STAIN FREE GROUT for filling tile joints up to 12mm wide  TAL STAIN FREE GROUT is especially designed to drastically reduce the   staining of highly porous tiles such as sandstone and slate, overcoming the “picture-frame” effect encountered with conventional grouts.
  • Suspended Slabs:
    • Option 1:  TAL Quarrygrout
      • Use grey or coloured  TAL QUARRYGROUT mixed 20kg with 5 litres of  TAL BOND (replacing the water in the mix) for filling tile joints 5mm and wider.  TAL QUARRYGROUT is suitable for use in joints up to 25mm wide. 
        Alternatively,  TAL BOND POWDER may be added to the grout mixing water, at a ratio of 1 x 1kg sachet per 20kg TAL QUARRYGROUT.
    • Option 2:  TAL STAIN FREE GROUT 
      • Use Light Grey  TAL STAIN FREE GROUT  mixed 20kg with 6 litres of  TAL BOND  (replacing the water in the mix) for filling tile joints up to 12mm wide  TAL STAIN FREE GROUT is especially designed to drastically reduce the staining of highly porous tiles such as sandstone and slate, overcoming the  “picture-frame” effect encountered with conventional grouts.
        Alternatively,  TAL BOND POWDER may be added to the grout mixing water, at a ratio of 1 x 1kg sachet per 20kg  TAL STAIN FREE GROUT.
  • General / WARNING:
    • Particular care must be taken to clean the grout off the tile face before it hardens completely. This is especially important when an additive such as TAL BOND or TAL BOND POWDER has been used.
    • A sample of the tiles to be used should be tested beforehand to ensure that no grout is absorbed into the tile body, causing permanent staining of the tiles.
    • It is important to use the stipulated amount of liquid in the TAL Grout mixture. When cleaning, a  damp,  not wet, sponge must be used. Over hydration (too much water) of the mix, or in cleaning, causes colour variations in the grout joints, and also affects the integrity of the grout, resulting in a friable product.

 

• MOVEMENT JOINTS
  • It should be noted that the lack of movement joints in a tile panel is a major cause of tile failure. They should be specified at the design stage to avoid placing them in heavy traffic areas and spoiling the visual effect of the tiles.
  • Movement joints should be located in both directions at maximum 5 metre centres for interior surface bed applications, and maximum 3 metre centres for suspended applications.
  • Movement joints should also be located around the perimeter of all floors, in all vertical corners, against obstructions fixed to the structural background and over all discontinuities in building materials, e.g. at interfaces of concrete and brickwork. In addition, movement joints should be located around any fixtures protruding through the tiled surface such as columns or stairs.
  • The joints should be at least 5mm wide and extend through the adhesive and tile layers. All construction / cold joints and structural joints in the background must be extended through the adhesive and tile layers to the surface in the form of tile panel movement joints. With regards to structural joints, the full width of the structural joints must be respected and extended through the adhesive and tile layers to the surface.
  • Where practical, the bulk of the depth of the movement joint can be filled with TAL SEALMASTER CORD.
  • Seal the joint using  TAL GOLDSTAR SEALMASTER 1000 polyurethane joint sealant in accordance with the manufacturer’s instructions. It is important that the joint sealant bonds only to the sides of the movement joint.
  • For the key requirements common to all tiling situations please refer to SANS 10107-2011, Code of Practice for the Design and Installation of Ceramic Tiling.

Should you require any further assistance or have any queries regarding the above, please do not hesitate to contact us.

Assuring you of our best attention at all times.

 

 

Yours faithfully,

SHARON MARGON

TECHNICAL ADVICE SUPERVISOR

©TAL 1972 & 1984

 

 

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