Windows – Canned spray foam vs. ExoAir foam tape
I noticed that builders will use canned spray foam to fill in the gaps between the window and the window bucks. The spray foam is messy and needs to be trimmed back on the interior and exterior since trim work cannot be done properly. I also question spray foams ability to expand and contract as window frames do over the course of the life of the home. I also have seen smoke pencil tests done after spray foam and there are noticeable air gaps between the window frame and buck.
There is a foam tape product made by Tremco called EXO AIR and it basically is installed underneath the window frame and window buck and the foam expands to close in the gaps. It stays flexible for the life of the window and is much cleaner and easier to trim a window once installed.
So why do window installers rely on canned spray foam so much when they are not airtight and messy to deal with?
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