THE BEST PLACE TO INSULATE A CONCRETE WALL IS ON THE OUTSIDE OF IT. THIS CAUSES THE
CONCRETE TO BECOME PART OF THE THERMAL MASS AND ADDS TO THE COMFORT AND EFFICIENCY OF THE HEATING SYSTEM. WHEN THE INSULATION IS PLACED ON THE INSIDE OF THE WALL IT CAUSES THE CONCRETE TO ACT AS A HEAT SINK.
PRODUCTS CONTAINING FOIL OR PRODUCTS USING EXPANDED POLYETHYLENE FOAM SHOULD NEVER BE INSTALLED UNDER SLABS!!
USING TWO INCHES OR MORE OF HIGH DENSITY FOAM BOARD IS THE ONLY INSULATION UNDER A SLAB THAT IS WORTH ANYTHING!!
Some of the products that in my estimation are worthless under a slab are RadiantGUARD®,
The Barrier™, Slab-Shield™, Insul-Tarp™, Reflectix®, The Barrier™, TVM rFOIL™,
