I don't recall where I saw it, but there is a product (similar to door & window flash, but wider) that goes on the plywood, along with a primer. You would need to start the application down at the ... read more
Verify that all window and door seals/weatherstriping is in good shape.
Check to be sure doors and windows are caulked properly (no gaps, cracks or missing).
If you have an attic access, treat it like ... read more