Foam Board Insulation Insect Problems
When insulating a foundation another thing you should worry about are insects, while foam boards don’t provide any nutritional bonuses for bugs, they’re ideal for tunneling. You might not be aware of this, but insect burrows can and will reduce the R-value and structural integrity of your foam board insulation. Usually, foam board manufacturers treat their products with a special insecticide.
A better solution for below grade walls in need of insulation is to install the foam board over the interior of the basement walls rather than on the exterior as is more commonly done. Interior applications prevent ground-dwelling insects from finding the foam board at all, and it eliminates the need for the inspection area where no insulation is allowed. Most jurisdictions require installing a fire-barrier over the foam board, and while this may add up some extra costs the thermal performance of this method is superior in most cases to the more common foam board application to the exterior of the foundation.
