Steel mesh

For a concrete structural floor where no screed is yet present, the underfloor heating pipes are bound to steel mesh.

The screed usually consists of a 5 to 7 cm layer of sand-cement or anhydrite. The mass of the floor acts as a heat battery — unlike milled heating, it takes longer for the heat to be released, but also longer to cool down. This is advantageous because the heat source cycles on and off far less frequently.

With less than 5 cm of space for the screed, only steel mesh is used and the sand-cement bonds directly to the structural floor. With more space, the screed can be laid as a floating floor. Edge insulation limits sound transfer to walls, and the reflective foil ensures uniform heat distribution.

The reflective foil has been given a misleading name — air is actually needed between the heating element and the foil for any reflective effect. To prevent downward heat loss, insulation from below is required. Aim for a floor insulation value of at least R=3.5 or higher. Can the structural floor not be insulated from below? Then tacker or stud plates offer a solution between the structural floor and top layer.

Once the installation is complete, a third party can pour the sand-cement or anhydrite. Unfortunately, the underfloor heating cannot be turned on immediately — for each centimetre of screed, one week of drying time applies. So 6 cm of screed means 6 weeks of waiting.