# Sheet Rock Over Concrete



## atmironov (Apr 27, 2010)

Hey Everyone,
Currently I am in the process of adding a garage and a living room underneath my 1906 San Franciscan Victorian, along with replacing all the brick foundations.
I am paying a contractor to do the concrete and iron work, but will do all the electrical, plumbing and finish work myself.

I have no experience when it comes to finishing partially subterranean basements.
The foundation walls will be about 3 feet below grade.
In the occupied space, there will be waterproofing installed on the outside of the concrete, but in the unoccupied space there is no waterproofing.

So, my question is what is the best way to sheet rock over the concrete.
Here are my thoughts:
Occupied Area - Shim the foundation out 1/2" - 3/4" with pressure treated plywood, then glue the sheet rock to that. 

Unoccupied Area - Sheet rock right up to the top of the foundation and leave the concrete exposed. Keep in mind that I have to have 1 hour walls.

Any advise would be greatly appreciated.

Also, if anyone is interested I post lots of pictures of the project here:
www.mironovcentral.blogspot.com


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## AllanJ (Nov 24, 2007)

Some cities require that the sheetrocked over exterior concrete wall have so much insulation. Example only: R-19 for the portion of concrete above grade (and exposed to the outside) and R-13 for the portion of concrete below grade.

The recommendation is to have a one inch air space between fiberglass insulation and the concrete itself. This necessitates a bigger stud cavity than you might otherwise have planned.

If the concrete has a painted on waterproofing, then omit the vapor barrier on the inside.


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## atmironov (Apr 27, 2010)

Alright,
I did some research, and I need to put in R5 rigid insulation...
So, I will be furring the walls with 7/8" hat channel...

Now, I live in San Francisco, and vapor barriers are not required, and in addition a waterproof membrane is being placed on the outer portion of the foundation walls.
So my final questions is placing some sort of water and or vapor barrier over the concrete recommended?

Thanks for your help.


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## Mr Chips (Mar 23, 2008)

atmironov said:


> So my final questions is placing some sort of water and or vapor barrier over the concrete recommended?


It's probably not a bad idea, since it will help keep mostiure from building up on the drywall, which could provide a home for mold.

I'm sure one of the pros here will correct me if i'm wrong. it's happened before....


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