Thoughts on the Plastic Layer in this Wall Assembly
I’ve sincerely enjoyed the many, many hours perusing this website and have learned so much. So thank you everyone. First, some background…my home was built with old lumber. Specifically, I tore apart 11 barns at the historic Narragansett Racetrack in Rhode Island in 1978. The wood is tongue and groove southern yellow pine as well as many 4×4 and 6×6 beams. Using this wood, my house was built on a shoestring.
Fast forward, I recently removed a concrete deck on the gable end side of my house only to find out the sill plate was totally rotted (like cardboard ready to collapse). I fixed that. Moving forward, I want to strengthen and insulate the house from the exterior with plywood, then foam board (zone 5 so would be 1.5 or 2 inches) then vinyl siding as the final exterior so I’m done with painting. Here is my dilemma…much to my surprise, I have discovered that there is plastic on the interior wall. The wall sandwich goes like this: interior drywall–> insulation batts —>plastic on the exterior side of the batts—>exterior wood wall then vertical wood siding.
1) Do I need to remove the plastic sheets? I really don’t want to because that would be a major interior overhaul.
2) Can I leave the plastic, remove the cheap vertical siding, add plywood and foam sheaths followed by vertical siding without worrying about moisture and rot? The wall sandwich would then be: interior drywall–>batts–>plastic sheets–>wood wall–>1.3 or 2 inch foam boards–>Tyvek (or similar) —>vinyl siding.
3) Am I asking for trouble down the road if I leave the plastic in place?
Thanks again for any help. BTW, I’m a 67 yo woman ready to retire but can’t until this is done!
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