Jump to content

Recommended Posts

Posted

I did a house today with EIFS on the front and chimney chases. When I was in the attic I noticed that the substrate looked like drywall...never seen that before (usually OSB around here). It was at the very least made like drywall, with paper encasing a hard, white chalky substance, and the words "water resistant" stamped on it. It wasn't green or anything.

Did any manufacturer use or allow such a substrate? What could it be other than some sort of wet location drywall?

Brian G.

Posted

I call it gypsum sheathing. We see it a lot on commercial buildings. Lately, the paper on it's been yellow. Used to be tan. I have no idea what the colors signify.

- Jim Katen, Oregon

Posted

Brian, just about every EIFS manufacture allowed this type of substrate at one time. I have found it more on commercial buildings. Up in your area FL Craine & Sons would have done most of it from around 1993 to 1998 from what I have seen.

One major problem was the delamination of the foam from the substrate. If nails were used they pulled out of the gypsum sheathing, if adhesives were used the paper face would pull loose from the gypsum. The better gypsum used a fiberglass reinforced paper over the gypsum (Glass Mat).

Posted

And I would've sworn a term like "exterior drywall" or "gypsum sheathing" was an oxymoron. Go figure. [:-dev3][:D][:-dev3]

Mucho gracias gentlemen.

Brian G.

Posted

I agree with all of the aforementioned. One thing to add, you'll usually see some form of asphalt paper or moisture retarder on the outside of the gyp sheathing -even though the gyp is moisture resistant.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...