For weatherization purposes, is it worth removing the trim around windows (and sliding doors, etc) and filling the gaps behind the trim with spray foam (or perhaps caulk?), or is it acceptable simply to caulk around the trim?

1 Answer 1


Adding expanding foam around windows and doors is a cheap way to add insulation. If you're willing to do the extra work involved in removing and reinstalling the trim, it's definitely worth doing.

Adding caulk alone might stop drafts but isn't as good of a thermal break.

Make sure you use an expanding foam that is specifically for windows and doors. This product will not expand as much in order to prevent malforming the frame.

  • Right on. +1. there are sometimes large uninsulated gaps around doors and windows and worth the effort to insulate them. Feb 22, 2014 at 17:44
  • @Steven - I assume you would caulk around the trim as well, once you reinstall it, right? Or would the expanding foam provide enough of an air break? Feb 23, 2014 at 2:38
  • Yes I would still caulk with a paintable caulk, but it's mostly cosmetic at this point to fill in any gaps
    – Steven
    Feb 23, 2014 at 13:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.