EPS under siding
Hi all, I have a weekend cottage on a lake here in middle GA that was built in the mid-80’s that is in need of some serious TLC. One of the projects I’m planning on doing is to re-side the house with Hardiplank lap siding. The current siding is cedar lap on top of 1” foil faced Expanded Polystyrene (EPS). The corners are set with ½” plywood and ½” GP particle board for shear strength. Currently, there is no felt or house wrap between the sheathing and cedar siding. Due to 10 years of lack of maintenance and woodpeckers; the current cedar siding is in really bad shape. After I remove the cedar siding; I was considering leaving the EPS in place and going on top of that with ½”OSB, house wrap, then Hardiplank. I want to keep the EPS for several reasons including; saving labor time, keeping EPS out of the waste stream and the additional insulation. My question is; will I actually be trapping moisture between the EPS foil face and the back of the OSB? Or should I keep the EPS, install housewrap and proceed with the new Hardi siding? I’d like to add OSB for additional shear and nailing strength. I’m aware that I will need to make extensions to all my door and window jambs if I add the OSB. Thanks!
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