When installing underfloor heating beneath carpet care must be taken to ensure the correct output system is installed and that the heating can be easily limited.
Usually the carpet is installed onto an underlay which is placed onto a screed, latex or levelling compound base, and we recommend installing the underfloor heating system into this base at an output of not greater than 160W/sqm. The heating should always be covered by at least 10mm of levelling compound or similar or, in the case of a screed, by 55mm. The thickness of the layer above the system helps the heating system to dissipate it’s heat and avoids ‘hot spots’ above each heating cable.
In these installations it is vital to install a quality, hessian backed carpet, or similar carpet that will allow the movement of heat into the room from the underfloor heating system. Care should also be taken to use a low Tog underlay and carpet suitable for use with underfloor heating and, as a rule of thumb, you should look for a carpet with a Tog rating below 2.0 and insulation with a Tog rating below 0.8. Roma by Ball and Young is one example of a low Tog rated underlay satisfying these requirements.