By: Tom Huempfner, VP of Sales & Marketing
For most of us the answer is yes but why the obvious question? I’m trying to call your attention to something that gets very little attention; perimeter and under-slab insulation.
Often overlooked, perimeter and under-slab insulation provide much needed thermal protection to a building but are usually given very little consideration by the building owner. It has become the norm to leave the decisions of under-slab and perimeter insulation up to the architect or the contractor. What type of insulation and how much insulation is a quick decision many times answered by; “do what you normally do” or “use the least expensive option”. Very typically 1” or 2” of rigid foam insulation is installed around the perimeter to meet minimum requirement of the building code requirement and never thought about again.
To avoid those cold feet and high energy bills insulate the concrete foundation and concrete slab as you would an above grade wall and roof. It is a very small one time cost to put additional rigid foam insulation on your building and you realize energy savings every month for life the building. Instead of R5 or R10 go with R20 which is typically the minimum R value of the wall and roof. If you use 15psi compressive strength Foam-Control® below-grade insulation the additional cost to go from an R10 to an R20 is only $.44 SF. The comfort of a warm floor and the savings from lower energy bills come back to the building owner every month. ICFs are a good way to meet or exceed R20 on your foundation wall. Learn about the nation’s largest mega mansion and ICF house.
Also realize perimeter and under-slab insulation should be moisture resistant, maintain its R value when exposed to moisture and have a minimum compressive strength of 15psi. Learn more about the performance of the various types of insulation after 15 years in the ground and avoid the discomfort of cold feet.