WIU should be installed with the foil side facing DOWN. Click “Read More” for details.
Warmup Insulated Underlayment is designed to be used in conjunction with our foil heating systems. It sits between the cold subfloor and foil heater product, reflecting heat upwards. It makes the electric floor heating more efficient and effective by reducing the time it takes for your floor to reach the desired target temperature during initial ramp-up. The foil backing also acts as an effective moisture barrier.