What depth of floor insulation do I need for underfloor heating?
A simple rule of thumb is to incorporate as much thermal insulation wherever possible below the underfloor heating system: the principals are the same for water as well as electric installations. For new build projects the insulation depth is easy to plan but in a typical refurbish situation for existing sub-floors, this is not always possible, especially where the overall finished floor height may restrict the depth available to add the thermal insulation. However, even a 6mm thermal layer directly below the underfloor heating will provide a noticeable difference in start-up times, bringing the floor temperature up to an optimum warmth within a much faster time. Fastwarm® thermal insulation boards are available from 6mm to 80mm. Fastwarm®-Xtra tile backer insulation boards are only available in 6 and 10mm.
