Concrete Floor

kevsprojects

I am looking to build (extend) a wall out about 3 feet or so into the garage from an existing laundry room. Just want to have some additional working space in the laundry area.

My concern is, the framed floor would be over the existing concrete floor of the garage. Footing - sill - floor joist etc.

I know this scenario will lead to moisture issues with the concrete floor. I wondered if a 6 mil vapor barrier and/or drylock would be a solution.

This area would also be "unaccessible" when completed. There would be no utilities involved, just the extra square footage is all I'm after.

Would the fact that it is unaccessible be an issue if there is no reason to access it? No plumbing, electrical, HVAC etc.

The moisture issues from a concrete floor beneath a typical wood framed floor is my concern.

Kevin

joecaption

Your post makes little since to me.
A picture, drawing, look over and rewrite your post would be a big help.

oh'mike

You should add a polly vapor barrier under the new floor joists---use plastic shims instead of wood ones.

Moisture should not be a big concern unless you know that the garage floor is a damp one--

any framing that rest on the floor should have foam sill sealer under it--as a capillary break.

Sill sealer is sold in a roll about 8" wide and is used under the framing at the foundation--Mike--

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kevsprojects

Tried to upload pics but get "bad request" messages ~

Yes, I will use the foam sill sealer on the sill. The floor joist would be above the concrete floor by about 5 or 6 inches, not in direct contact with the concrete garage floor. Would an inspector have any issues with the "unaccessible" space?

oh'mike

I doubt if that will be an issue---It will need to be a fire proof seal between the floor and the wall structure---do check with the building department--

They are concerned with a gasoline spill in the garage--seeping under the flooring---
Requirements vary by location--so check before building----

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kevsprojects

Ok great. That's the kind of tips I'm looking for.