Edge Insulation

The insulation phase is crucial for an underfloor heating floor. Mainly, heated slabs radiate outward rather than downward, so insulation on the edges of the slab is most important. Remember that your slab will be about 25 degrees C. Any cooler surface in contact with the slab will try to steal its heat. Edge insulation is recommended for both in-slab and in-screed systems. For in-screed systems we install Rehau Edge Insulation. For in-slab systems the builder is responsible for installing vertical edge insulation.

The Building Code of Australia states “Slab edge insulation is usually sufficient, as approximately 80 per cent of the heat loss occurs through the edge. Install edge insulation before the slab is poured. Do not install insulation under concrete edge beams. Follow the manufacturers directions, particularly regarding the placement of the insulation in relation to the waterproof membrane. In termite prone areas precautions may be needed. Consult your local building information center. R1.0 polystyrene boards on the slab edge give a total R-value of at least 2.2 (insulated section only)”