Stone Over Drywall

fakie99

i know owens corning specifies that cultured stone can be installed w/lath over existing drywall, but how many of you actually do this? i have typically removed drywall, and done either plywood w/tar paper and lath, or installed cement board, then stone over that. i have a client who is on a tighter budget and lath over drywall would cost less for sure. but i am not sure i feel comfortable doing it that way. any thoughts - thanks.

genecarp

No problem fakie-----lick and stick, on drywall

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jomama

We go over dry wall all the time, but I ask the builder to have the drywaller spray the FP surround with the rest of the walls to minimize any wicking of moisture from th mort. I've actually only had issues with a FP surround when using tarpaper over OSB on a raised hearth. I think the OSB must shrink or swell or something because we've had a few crack (mortar) where the raised hearth & wall come together. Since those, we've been lapping our lath down onto the hearth, seems like it's working so far. I'd be interested to hear others take on it though.

fakie99

hmmm....enlightening. thank you guys.

Stone

You can actually put cultured stone on just about any wall. You don't even really need a substrate like drywall or plywood (although I don't personally recommend this) and there is a type of metal lath with felt paper attached which Owens Corning recommends for bare stud walls. Actually on the exterior they recommend only nailing into framing anyway, because they consider nails elsewhere as being possible sources of moisture penetration. I have done hundreds of jobs over drywall with no problems.

MasonryPro

In regard to one of the posts here, you cannot simply install manufactured stone on drywall alone. The only strength that would have is the drywall's paper exterior - very unstable.

The correct way to install the material is to put a vapor barrier on the drywall and then nail your mesh into the studs for support. Extra staples are sometimes beneficial, as it allows the mesh to adhere closer to the wall, avoiding "bubbles" in the mesh. Bubbles can cause cracking not only in the mortar joint but can allow water to seep behind the stone in an exterior application, causing the stone to break its bond and fall off!

Staple sizes and procedures, mesh overlaps, and corner preparation as well as proper mortar mixing and installation are critical to a successful manufactured stone installation.

Although manufactured stone installation is somewhat easier than other masonry projects, there are still tips and tricks masonry professionals employ that adhere to the standards of masonry aesthetics and installation.


Justin
Mastercraft Masonry
Professional Masonry Since 1974

Tscarborough

There are some types of faux stone that can be adhered directly to drywall, although it is not a manufacturers recommendation. Stone such as Profit by Cultured Stone or Stacked Stone by Eldorado Stone can be applied to a properly prepped raw sheetrock wall.

A product such as Parex 121 base coat can be troweled on, and then the stone applied with a good modified thinset. Under normal conditions, I have no problem warrantying this application. I would never advise it for a DIYer, or for anyone else not willing to accept the liability, but it works fine for small interior wall details (I would not do it on a wall over 9' or in a high traffic area or in any seismic zone).

The reality is that there is almost no application where this would be desirable, though.

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