Ceramic tiling to raised access flooring

The current rash of conversions of office buildings to residential use has meant that tiles are increasingly being laid on existing raised access flooring. Tilemaster Adhesives Ltd – Kerakoll Group is currently the only UK tiling products supplier to offer a system that provides failsafe tiling to this type of flooring using its Kerakoll brand of products.

The system offers the further advantages that it is low profile, with short installation times allowing fast completion, and that all products have very low VOC emissions, improving air quality and safety for the tile fixers.


The first step is to apply a layer of Biotex, Kerakoll’s reinforced anti-fracture membrane. This is made from recycled, thermo-bonded polyester and is specifically designed to absorb shear stresses between substrates and bonded coatings. It is used here to reinforce the platform before laying ceramic or porcelain tiles. In addition it is only 0.65mm thick meaning that it adds very little to the height of the floor.

The membrane should be fixed with Biogel Extreme, a hybrid gel adhesive that bonds everything even in the most extreme working conditions. The adhesive strength (4.5 N/mm²) is 500% superior to a class C2 cement-based adhesive after 24 hours, and ten times more deformable (> 50mm) than a class S2 cement-based adhesive. It is also easy to spread, being five times less viscous than a polyurethane adhesive. It achieves shear adhesion for porcelain tiles, after seven days, of 6.5 N/mm² and tensile adhesion of 4.5 N/mm² after 28 days. These qualities make it the perfect adhesive to use for this system, guaranteeing excellent adhesion to the metal platform. In addition, despite the fact that it is classified as an R2 adhesive, Biogel Extreme does not contain epoxy resins and is non-toxic, non-hazardous, and made from solvent-free raw materials.

Tiling & grouting

Once the Biogel Extreme has set (about 4 hours), tiling can begin. The same adhesive should be used for the tiling to ensure there are no problems with the installation.

Next, the tiles should be grouted with Fugabella Color. a hybrid resin-cement grout suitable for internal and external use which is able to receive foot traffic after approximately 3 hours. This is available in 50 different colours, chosen by Piero Lissoni to coordinate with modern interiors, so perfect for residential conversions. The purity of the materials employed in the grout along with the use of specific natural additives gives reduced water absorption, lower levels of joint staining and complete protection from common acid pH substances. A revolutionary bonding system gives superior resistance to abrasion of 425 mm³ for Fugabella Color after 72 hours compared to 970 mm³ for a cementitious grout.

The final step is to seal any expansion joints with Silicone Color, a decorative sealant for tiles available in the same colours as Fugabella Color. It has low VOC emissions and a solvent content of ≤ 5g/kg.

Technical and specification support

Tilemaster Adhesives team is more than happy to get involved in the specification process to ensure that the right products are chosen to enable the project to run smoothly without any problems once complete. Please do contact them for further advice and support.

Tilemaster Adhesives Ltd – Kerakoll Group