Which WarmlyYours floor heating systems can go under carpet, how each is installed, and where they are approved.
Two WarmlyYours systems can heat a carpeted floor. Which one fits depends on how the carpet is installed, so start by asking whether it will be glued down or stretched in over a pad.
Glued-down carpet: TempZone™ Cable and Ruler Cable
- Secure the cable firmly to the subfloor so it cannot float, then embed it in a 3/8-inch layer of self-leveling underlayment. Prime the floor first if the underlayment manufacturer requires it.
- Glue the carpet to the cured underlayment. The floor covering must not exceed an R-value of 1.
- The cable manuals list carpet installation as U.S. only, and ask you to verify the installation complies with local electrical code.
- Carpet manufacturers may set a maximum floor temperature; set the thermostat limit to match.
Stretch-in carpet over a pad: Environ™ Flex Rolls and Environ™ Easy Mat
- Environ heaters go directly on top of the carpet cushion and directly under the carpet, with no mortar or underlayment over them.
- This assembly is approved in the U.S. only, not in Canada.
- The carpet must be ¼ to 1 inch thick. Rubber- or foam-backed carpets are not compatible because they trap too much heat. The pad must have a density of at least 6 pounds per cubic foot.
- Keep the heater at least 1 foot from the carpet edges so the power stretcher cannot damage it, and never install permanent fixtures over it.
- Environ Easy Mat is no longer sold. Existing Easy Mat installations follow the Easy Mat manual.
For the full Environ Flex carpet-and-cushion assembly over a slab, see Environ Flex under carpet over a concrete slab.
Sources: TempZone cable manual, sections 1.1–1.2, 2.1.7, 2.1.12, 2.1.16, 5.4.2 and 5.4.5 (PDF pp. 3–4, 16 and 18); TempZone Ruler Cable installation manual, PDF pp. 3–4 and 16; Environ Flex installation manual, Installation Under Carpet – USA Only (PDF pp. 10–13); Environ Easy Mat installation manual, PDF pp. 2 and 8–10.
