On Sep 13, 10:34*am, wrote:
On Sun, 13 Sep 2009 08:14:21 -0400, "John Gilmer"



wrote:

What's the alternative?

drywall over OSB or plywood

Oh, I didn't know where you were "coming from."

drywall is pretty weak material, esp for a garage

It depends on what you need the strength for. * If you intend to run your
car into the wall then if you are stuck with 2x4 uprights, the plywood or
OSB would make it slightly stronger. * If that's your problem and you are
starting from scratch, you can over design the wall and make it from 2x6
material with the same spacing. * That would be about twice is resistant to
your car's bumper.

OSB is pretty cheap but has decent strength

Drywall might not be as strong as OSB but it still makes the wall much
stronger. * *For repairability, I would prefer the drywall and the fire
resistance is a bonus. * *If you want strength, use two layers and/or
thicker than 1/2".

THE weakness is from moisture. * You can get "no paper" sheet material but
it's much more expensive and heavier. * *I not sure how well OSB will handle
moisture either.

Generally not worth crap when it gets damp. It gets real soft and
swells to twice thickness, then falls apart.



Generally not worth crap when it gets damp. It gets real soft and
swells to twice thickness, then falls apart.


are you speaking of OSB?

timber structural panels (OSB or plywood) are not meant of continuous
or even intermittent wetting beyond (during construction exposure,
before "dry in") .....timber construction is meant to be kept dry.

The fact that continuously wetted OSB swells & flakes is well
know...but continuously wetted plywood (as in a bathroom subfloor
subjected to long term leak) probaly should be replaced as well.

I threw together a piece of crap shed to store some stuff outside (in
the side yard of the garage). Stick framing, 3/8" OSB "siding" &
roof sheathing; no paper, no roll roofing, no paint. It lasted just
fine for a few years (like 3 to 5) in the SoCal sun & rain. Granted
we only get ~15 inches on average. The stuff would get wet but then
dry out. When it can time to demo it, there was not substantial loss
of strength; yeah the surface was flaky but not terrible.

cheers
Bob