Check the underlayment manufacturer’s requirements before covering TempZone cable or Flex Rolls.
Use a self-leveling underlayment whose manufacturer approves it for the intended substrate, electric floor-heating system, and floor covering. “High quality” by itself does not establish compatibility.
The TempZone instructions recommend priming the subfloor before laying out the cable or rolls so the primer can cover the surface completely. Follow the underlayment manufacturer’s preparation, primer, thickness, and curing instructions.
Secure the heating element before the pour so it cannot float to the surface. Keep the heating wire and factory splice fully embedded as required by the applicable TempZone manual.
Do not energize the heating until the thinset or self-leveling underlayment has fully cured. Confirm the complete floor assembly and its temperature limits before installation.
Sources
- Manufacturer instructions (publication 9748), PDF p. 4, sections 2.1.14–2.1.16.
- Manufacturer instructions (publication 4588), PDF pp. 5 and 11.