Can Foam Board Insulation Be Used Between Studs Instead of Batt Insulation?
This application is not typically recommended for the following reasons:
Rigid foam board pieces are difficult to fit snugly between studs so you would have to spray foam to fill any gaps.
Unlike loose-fill or batt, foam board insulation can’t easily be cut to perfectly contour around pipes or wires.
Due to flammability issues local building codes won’t typically allow more than 4” rigid foam board on the interior side of the wall. This thickness of 4” would only provide R-16 to R-20 depending on the type of rigid foam insulation used and that would not meet code on its own in some municipalities.
Rigid foam board insulation such as Halo Exterra and Halo Interra are best used as a continuous layer of insulation on interior and exterior surfaces of walls.