Cut-off pieces of foam from the ICFs and the underslab insulation could be thrown in the trash – or used for another purpose. Rather than throwing scrap foam pieces in the trash we stacked them against the front foundation wall of the house against the dimple mat. This area will be backfilled and at the foundation corner a boulder retaining wall will be built. The foam will cushion the dimple mat from the boulders and it will add more insulation to the wall. Granted, the Amvic Plus 3.3 ICFs are already giving us R-30 basement insulation so the performance is already good. The extra R-15 pushes the R-value to 45.
