Solving tiling challenges is what the new cementitious powder from TAL aims to resolve.
Professional tiling contractors and DIY enthusiasts can overcome tiling challenges such as the potential lifting of tiles linked to surfaces that are dense, impervious or smooth, by using the new TAL Keymix powder primer. This forms part of a tile adhesive priming system that creates better adhesion to the surface, when mixed with TAL Keycoat latex-based liquid.
Launched in February 2016, TAL Keymix is a cementitious powder primer used in a 2:1 volume mix with TAL Keycoat. The TAL Keymix primer slurry is used to prepare the surface and enhance the bond of the adhesive onto the surface substrate. “It offers phenomenal adhesion to most dense, impervious and smooth surfaces, such as power-floated or steel-floated concrete and screeds, existing tiles and glass, to name a few,” explains Sharon Margon, Technical Advice Supervisor at TAL.
When the surface is dense, smooth or impervious, it tends to have low porosity and little suction, which offers no mechanical key for the adhesive. These surfaces have to be suitably prepared, either by roughening the surface, which is time-consuming and messy, or by priming the substrate. A TAL Keycoat and TAL Keymix slurry priming coat will enhance the adhesive bond onto the smooth or dense substrate.
In contrast, very porous substrates may draw (leach) the mixing liquid from the adhesive into the substrate, which will adversely affect the integrity and performance of the adhesive. Furthermore, contamination on the surface, such as dust and loose particles, will act as a ‘bond breaker’ and prevent the adhesive from bonding onto the substrate. Sharon cautions that incorrect or inadequate surface preparation can adversely affect the integrity of the installation and may lead to an installation failure.
“In all tiling installations, correct background preparation is paramount to a successful tile installation,” Sharon says. “Substrates must be allowed the minimum curing or drying times, be integrally sound and of a quality and consistency suitable for tiling. All damaged, defective, deteriorated or hollow sounding areas must be removed and rectified, and all surface contamination should be removed.”
When tiling onto conventional reinforced suspended concrete slabs, the TAL Keymix primer slurrycoat, applied to a minimum 2 mm thickness, improves the flexibility of the tiling installation. This, together with correctly placed tile panel movement joints, will help prevent the tiles from cracking and lifting.
It is important to bear in mind that TAL Keymix cannot be used on its own, and must be mixed with TAL Keycoat liquid in a 2:1 volume ratio. Adding the powder to the liquid ensures better dispersion and prevents lumps from forming. Once sufficiently mixed, TAL Keymix primer slurry is brushed onto the surface with a builder’s block brush. “Due to the innovative formulation, this TAL Keymix primer system has excellent workability and drying time,” Sharon concludes. “Tiling can commence after four to six hours once the TAL Keymix primer slurry is touch-dry, in other words, there is no visible transfer when wiped or rubbed.”