How to install windows over exterior foam insulation
The primary difficulty is figuring out how to build out the rough window opening to accommodate the thickness of the foam board. This leaves people unable to understand how to properly attach the nail fins and integrate the foam break with the exterior trim. It also creates confusion around getting final window measurements before the siding is completed.
Overview
People affected2 accounts across 1 forum
Workarounds found2 items attempted
Community agreement3 total upvotes
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
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- 1doing custom trim work on the insideDid this help you?
- 2ordering windows with a custom jamb depthDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
Where this came up
People with this problem also raised
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