Using insulation board on top of OSB and under siding
I have a 1500 square foot house with a 500 square foot bonus room upstairs. I have a downstairs window that is broken and I need to replace. It is a vinyle window with a nailing flange.
I live in southern Kentucky (42206). My house has 2×4 walls with fiberglass batts in all walls including the interior walls.
I have osb outside walls with no tyvec or anything on them. Nailed directly to the osb is vinyle siding.
Since I need to replace this window and it is on a small north sided wall, I got to thinking if it would be a good idea to remove the siding, replace the window, then install 1/2 inch insulation board on top of the osb, then put back the vinyl siding? Maybe, as I get time working my way around the whole house with this process.
I remember when the house was built in 1998, plastic vapor barrier was used on the inside of the wall covering the batts. Will putting 1/2 inch insulated foam sheeting cause a moisture problem? I cant seem to find a direct answer to this.
Also, is it possible to put the foam on top of the nailing flange of window instead of removing all the windows and re installing on top of the insulation? Or would that cause water problems?
I appreciate any help!
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