Are Washable Rugs Safe for Underfloor Heating?

A low-pile rug on a woven backing is one of the better things you can put over underfloor heating. A thick one with a rubber back is one of the worst.

Why pile height matters

A rug is insulation. The thicker it is, the more heat it traps between the floor and the room — which makes the room colder and the floor hotter than the system expects. Most underfloor heating manufacturers specify a maximum combined thermal resistance for anything laid on top, and a deep pile rug on a thick underlay exceeds it easily.

A flat, low-pile rug on a thin woven backing has a low thermal resistance and lets heat through with very little loss.

The backing is the other half

A solid rubber or latex sheet is both an insulator and a vapour barrier. Trapped heat also accelerates the breakdown of the latex itself. A woven cotton backing is neither.

Practical points

• Bring the floor up to temperature gradually the first time, rather than from cold to maximum.
• Do not run the system at maximum with a rug newly laid over a cold floor.
• Check the floor covering guidance for your specific system — the numbers vary.