Substrate preparation

Installing an underfloor heating system doesn’t affect the choice of stone type in any way, but choosing the right adhesive is essential. For these systems, only flexible (S1) adhesives are used, such as Weber Marmo Plus or Weberset Portelanat Max².

After checking door and interior stair clearances, and after installing the plumbing and electrical systems, the underfloor heating system (pipes or cables) is installed. It’s best for it to already be embedded in a screed, over which the natural stone flooring is then installed.

For water-based heating systems, pipes must be embedded in a cement-based screed. This should be at least 6.5 cm thick. Once the screed is poured, it’s left to dry.

If the pipe system is embedded in a polymer compound, this should be at least 1 cm thick above the pipes.

For electric underfloor heating systems, a layer of adhesive is first applied with a notched trowel, then the cable network is laid, followed by a second layer applied with a smooth trowel. Once this layer dries, another layer is applied with a notched trowel. The larger the tiles, the larger the trowel and notch size chosen. Tiles are laid one at a time on the floor, pressed gently into place.

Alternatively, a self-leveling screed can be poured over the cable network. Once it has set, the surface is clad with adhesive using the usual technique.