GENERAL SPECIFICATION FOR FIXING NATURAL STONE (LIMESTONE, QUARTZITE, SANDSTONE OR SLATE) TILES ONTO INTERIOR RENDERED WALLS, AND ONTO INTERIOR SURFACE BEDS AND SUSPENDED SLABS
Please note that ‘general’ specifications are issued for information purposes, and should not be used as project specifications.
As each and every project needs to be assessed individually on its own merits and characteristics please contact the TAL Technical Advice Centre for a project-specific detailed materials and methods specification for specific projects.
It is important that the tile selected is suitable for the application, preferably against a written Supplier’s specification. Factors such as water absorption, irreversible moisture expansion, MOR and PEI ratings, chemical resistance and overall stability of the product need to meet the requirements of the service conditions.
The backs of all tiles must be clean and free from dust and contaminants. Friable or powdery products must be primed with a slurry consisting of 1 part TAL KEYCOAT to 2 parts TAL KEYMIX powder or 2 parts TAL GOLDSTAR 6 or 12 powder (by volume) prior to the tiles being fixed. This coat should still be TACKY when the tiles are bedded into the adhesive. Natural stone products must also be tested for inherent delamination prior to fixing.
Please note that any “wet” areas, such as showers or balconies, should be waterproofed using TAL SUPERFLEX or TAL SUREPROOF waterproofing compounds prior to commencing tiling. Please feel free to contact us for a specification for waterproofing and tiling these areas, as well as for technical literature on any of our products.
TAL PRODUCT REQUIREMENTS
The Tal products required for this installation are as follows ;
TAL KEYCOAT *
TAL GOLDSTAR 6
TAL BOND / TAL BOND POWDER
TAL QUARRYGROUT / TAL STAIN FREE GROUT
NOTCHED FLOOR TROWEL
SPACERS
TAL SEALMASTER CORD
TAL GOLD STAR SEALMASTER 1000
Special note must be taken of the following :
Adhesive System :
We have specified the use of TAL GOLDSTAR 6 rapid setting high strength adhesive for the installation of these tiles. However, if timing on this project allows for a quick setting adhesive option, then TAL GOLDSTAR 12 can be considered.
The advantages of using TAL GOLDSTAR 12 are as follows :
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TAL GOLDSTAR 12 has a longer pot life (pot life of 4 hours, grout after 6 – 8 hours, and traffic after 12 hours)
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TAL GOLDSTAR 12 is more cost effective than TAL GOLDSTAR 6
It is however important that newly installed tiles are protected from traffic (other trades, etc) for a minimum of 12 hours, while the adhesive sets. This is especially important in fast-track installations.
Note : If a white or light-coloured natural stone tile is to be used we recommend that a sample of the tile be tested prior to fixing. If the grey adhesive shows through the tiles in the form of ‘staining’, we then recommend that TAL MARBLEFIX, light-coloured rapid-setting adhesive, be used.
Surface Beds:
All surface beds should have a damp proof membrane (DPM / DPC). Should there be no damp proof membrane below a surface bed or if prevailing moisture levels do not attain 5% (75% RH) or less, it is recommended that TAL X-CALIBUR X-SHIELD VAPORSTOP HB (vapour barrier) be applied prior to tiling to eliminate potential problems associated with excessive moisture in the substrate (such as slow- or non-curing of the adhesive, efflorescence on grout and porous tiles, etc). TAL X-CALIBUR X-SHIELD VAPORSTOP HB is a moisture tolerant, 100% solids epoxy barrier coat that prevents the passage of water vapour and moisture through concrete slabs. Please contact TAL for more information on the application of VAPORSTOP HB.
Suspended Applications:
Tiling onto SUSPENDED concrete slabs require special precautions to be taken as the installation is prone to increased movement caused by slab deflection and creep, loading on the slab, etc. TAL BOND or TAL BOND POWDER needs to be incorporated in the adhesive and grout mix, or a single part flexible adhesive such as TAL GOLDFLEX needs to be used to allow for the increased movement.
NOTE : All Ground Floor levels with Basement / Parking levels below should be construed as SUSPENDED slabs.
Tile Panel Movement Joints & Perimeter Joints:
It should be noted that the lack of movement joints in a tile panel, or poorly constructed joints, is a major cause of tile failure. Joints must be created at the required spacing and must be well raked out to remove all traces of adhesive residues, debris, contamination, etc, ie the joint must extend through the tile and tile adhesive layers. These joints must be filled with TAL GOLDSTAR SEALMASTER 1000 Polyurethane Joint Sealant (and suitable backing cord where applicable) in accordance with the manufacturer’s instructions. (See later detail of correctly constructed tile panel movement joint and perimeter joint.)
GENERAL SPECIFICATION FOR FIXING NATURAL STONE TILES ONTO INTERIOR RENDERED WALLS
- BACKGROUND PREPERATION
- Allow all new wall rendering to cure for at least 14 days. The rendering must be firmly attached to the substrate, must be integrally sound (no crumbling, cracking, etc) and must be of a quality and consistency suitable for tiling. All damaged, defective, deteriorated or hollow sounding areas must be removed and made good before proceeding. Renders should be left with a woodfloat finish and should not be skimcoated with gypsum plaster. The surface must be clean, dry, firm and sound and free from all traces of dust, loose particles and surface contaminants.
- If the surface has been woodfloated (rough) it is possible to commence tiling. However, if the surface has been steelfloated (smooth, dense) it will be necessary to first key the surface with a slurry consisting of 1 part TAL KEYCOAT to 2 parts TAL KEYMIX powder or 2 parts TAL GOLDSTAR 6 or 12 powder (by volume), which is applied by block brush. Allow this slurry coat to dry for 4 – 6 hours before applying the adhesive. *
- ADHESIVE SYSTEM
- Apply TAL GOLDSTAR 6 rapid-setting adhesive to the background using a notched trowel.
- In this tiling situation it is imperative that there is a solid bed of adhesive at least 5mm thick behind each tile. We would recommend the use of a notched TAL 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.
- 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.
- NOTE : Ensure that heavy and /or large format tiles are well supported by means of a batten or some type of mechanical device until such time that the adhesive has set sufficiently. In this situation it will be 6 hours.
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