Framed basement wall – what sheathing to use?
Siffe| Posted inGreen Products and Materialson
Hi, my builder proposes the basement end wall (10 ft. high) to be framed and covered with stucco to match the concrete side walls. He says to frame it vs. using concrete may cost a couple of $thousand less. The basement will be uninsulated and unheated.
Problem is what to use for sheathing that doesn’t offgas. That excludes OSB and regular plywood. DOW SIS? Marine grade plywood? Advantech? I guess the same goes for the unvented attic sheathing, but maybe not as much of a concern (blown-in FG there). Does anybody have any other suggestions? Thanks much.
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Replies
Ed,
First of all, it's important to emphasize that most homes with OSB and plywood don't experience offgassing problems. The few cases I have heard of that implicated OSB involved OSB that got wet. I have never heard of indoor air quality problems arising from plywood sheathing.
To answer your question:
1. The obvious choice for wall sheathing (if you are trying to avoid OSB and plywood) is diagonal boards. If you purchase them from a local sawmill, they often cost less per square foot than plywood.
2. Another option is rigid foam. If you choose to sheathe with foam, you'll have to come up with a way to brace the wall (although frankly, if your wall has concrete on both sides and is topped by a framed floor, there isn't much of a bracing concern; check with an engineer on this).
3. Your third option is gypsum sheathing, a common material on commercial jobs. The most common brands are made by Georgia Pacific (DensGlass, DensGlass Gold, DensArmor).
Thank you, Martin. I have found out that OSB has been low-emission since 2008, so I will go with that.