All product types Consult with the radiant heat system manufacturer to ensure that the system is compatible with vinyl flooring. If so, concrete subfloors with electric and hydro systems are acceptable. Underfloor heat mats are not an acceptable installation method. In-floor radiant components must be a minimum of ½" (13mm) below flooring. Floor surface temperature should never exceed 85°F (29°C). Heating system should be operational for at least two weeks prior to installation to calibrate temperature settings.