Prep Needed for Drywall over Concrete Wall?

[ugosplat]

I have an attached garage with no water issues and the wall that is shared with the house is concrete for the 1st ~12 inches in the garage. The drywall on this wall starts above the concrete and the entire thickness of the drywall sticks out beyond the concrete. The other walls in the garage have drywall that goes all the way to the garage floor.

I am interested in covering the concrete here with drywall so the wall looks like the others in the garage. My thought is to screw the new drywall into the exposed wood in the picture and then use adhesive on the concrete for extra support.

QUESTION: I am running into confusion when trying to determine what, if anything, I should do for a vapor barrier (e.g., 6mil plastic on the concrete or paint the concrete with drylok, etc.). I am looking for any suggestions on how to best prep the concrete before putting drywall over it.

Thanks

 

[sands35]

I'd put on a wood baseboard rather than drywall. Prime both sides.

 

[Dan in Pasadena]

You're just asking for opinions so here goes:

I'd NOT trust that there will NEVER be a "water issue". This falls under the maxim of,
"Better to have it and not need it, than to need it and not have it", i.e. a barrier of some kind.

Drylok works pretty well and if you've been through a winter with normal rainfall and still don't think there's any water issues then I'd consider using it. Then I'd put some pressure treated 1x "sleepers" on the wall with galvanized fasteners and screw green board to it.

This prep will cost very little in dollars but WILL take a few extra steps. But then you'll have peace of mind knowing you won't likey have to tear it off to repair it.

 

[mtmgtz]

I'd put on a wood baseboard rather than drywall. Prime both sides.

Agreed. You don't want drywall all the way to your concrete floor without some sort of baseboard anyway since it will get beat up easily.

 

[wssix99]

That strip of concrete is your gas curb. A good quality grinder and masonry blade (depending on the amount of material, you may want a diamond blade) will allow you to grind the curb flush to the existing wall. If you start a full sheet of drywall on the bottom course, you may not need to physically attach the drywall to the concrete at all.

Concrete can wick water so generally you would want to isolate materials like drywall from it, but being that your gas curb is within your foundations, I'd expect it to stay dry and not five you any problems.

 

[Average_Joe]

I would cut 24 1/2" above the floor. Glue some plastic over the concrete and up the wall a little. Then put some glue on the plastic and install a 24" piece of drywall, keeping it ~1/2" above the floor. Mud/tape the seam, sand and paint. If you want to run baseboard, I would use glue and a brad gun to cross-nail it on.

 

[ugosplat]

Thanks for the tips and insight guys, they have given me some additional things to think about (especially the comment on this being a gas curb - a quick google search on that helped out my understanding of what I am dealing with).

I am currently leaning towards putting plastic over the gas curb and then using greenboard over the plastic, leaving space between the greenboard and the floor. Then, I am thinking vinyl or rubber baseboard molding to cover the gap between the bottom of the greenboard and the floor.

Average_Joe - Is there context for why you suggest cutting 24 1/2" above the floor? e.g., at the moment, I have ~2 inches of wood showing and I am wondering if cutting further up would be useful for me.

 

[Average_Joe]

Average_Joe - Is there context for why you suggest cutting 24 1/2" above the floor? e.g., at the moment, I have ~2 inches of wood showing and I am wondering if cutting further up would be useful for me.

It would give the strip some more strength and make the joint stronger. The drywall would crack with the wall/curb joint in line with the drywall joint. I was originally going to say 48", but went 24 to save material.

A commercial style vinyl wall base, like you said, is also a good option for base.

 

[wssix99]

I am currently leaning towards putting plastic over the gas curb and then using greenboard over the plastic, leaving space between the greenboard and the floor. Then, I am thinking vinyl or rubber baseboard molding to cover the gap between the bottom of the greenboard and the floor.

You can't go wrong with that. (I had to use some plastic where I had drywall right up next to a piece of concrete exterior wall and its working well.)

One other thing you might do is back up the drywall joints that cover the curb (and presumably aren't secured to the concrete) with some sheet metal or 1/8" hardboard and then use construction adhesive to glue everything together to prevent any cracking after you tape it.

 

[jhelrey]

Use PVC "wood"... No rot, etc

 

[ugosplat]

hmm, while expensive, pvc board looks pretty interesting. looks like i could get board that is 1/2" thick and 24" high -> http://www.homedepot.com/p/Veranda-...ersible-Cellular-PVC-SHEET-H120ZWS1/203836508

jhelrey (or anyone else) - have you used pvc board before? Think it can be skim coated/painted? I'd like it to look similar to the drywall that would be above it in my scenario.