How do I insulate an existing slab before I install SunTouch?
Some kinds of anti-fracture or crack-isolation membranes have minimal insulating properties. They are secured to the slab and then you put WarmWire or SunTouch mat on top. At least a good 1/4 inch insulating material will help reduce the heat losses into the slab below. Thicker insulation material tends to have a better R-vaule. Check with your local flooring dealers for products that are appropriate for radiant floors.
