spray foam around windows — is it better than sealing with caulk front and back?
SoundBuild
| Posted in Energy, Heating & Insulation on
I have a hard time believing that spray foam around windows is better than simply using caulk to seal the inner and outer edge of the window (with a foam backer where it’s bigger than 1/4″).
Does anyone know if Title 24 acknowledges this?
Replies
Spray foam around windows offers superior insulation by filling gaps completely, reducing energy loss. It forms a tight seal that prevents air leaks more effectively than caulking alone, ensuring better temperature regulation indoors. For long-term energy efficiency and improved comfort, combining both methods—caulking for initial sealing and spray foam for insulation—can provide optimal results.
The caulk might provide a good air seal n the short term — and maybe long term if it’s a good (very elastic and sticky) sealant. But, unlike foam, it won’t provide any r-value (insulation).
I think there’s a study out there somewhere that shows dead air is as good as foam. All foam does is trap air…