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Community and Q&A

Wall Assembly Retrofit

cutrightrc | Posted in General Questions on

I am looking for some direction on the best way to handle my wall assembly. The house was built in 94′ just north of Raleigh NC. It has poly behind the drywall, r15, fiberboard sheathing, and masonite siding with vinyl over it. The vinyl was added a year after the house was built as part of a lawsuit with the subdivision.

We are about to build an addition on the house and do some other exterior work. I am planning on residing the house in the process but have concern on how to improve the air sealing of the exterior with the fiberboard and not increase moisture issues on the poly behind the drywall. I have yet to find signs of dampness or condensation on any drywall sections that I have worked on the last few years but I don’t want to change something that would cause the issue.

Can the fiber board be sealed? Is replacing it better option? Is taping the WRB the best option? Will exterior insulation help or hurt the poly behind the drywall?  Thanks for all the guidance.

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  1. user-2310254 | | #1

    Hopefully the experts will weigh in. I would worry about the wall's drying potential. Poly (a vapor barrier) on the interior is risky in most climates. Vinyl siding on the exterior might also reduce drying potential to the exterior.

    If you're planning to reside, it's a good time to check the walls and opening for any bulk water intrusion. If it were my house, I'd also consider installing the new siding on furring strips to create a drainage air gap.

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