Converting attached car port to living room - foundation help....

[Richard Holliingsworth]

Hello:

Please tell me if I can do this......

I have an attached car port that is in great shape, but the slab is 16 inches below the house floor. In order to bring the new floor up "close to" level with the existing house floor, I would like to lay 2x12s up on end on top of the slab as the floor joists (I'll run the HVAC/Plumbing/Electrical through these), then nail on the sub floor, then build the 3 remaining walls and stand them up to become the new outside walls.

Is this the right way to do this? Any advise will be greatly appreciated.

Thanks, Richard

[Joe Bobst]

Yes, if your building codes will allow it. You will have pull a building permit, show the inpectors compliance with foundation requirements, etc. In all it will be a good learning experience. You will find that your officials can be very helpful in avoiding problems with your project. Good luck.

Joe

[Dan G]

If I am understandig the issues, you will need to do quite a bit more.

Code will require a footing to frost line under any load bearing and exterior walls in an occupied space. Your carport probably has no footing. By the time you saw off the edge of the carport to dig and pour a footing and stem wall, you may as well consider pouring a slab. If you use joists above the carport slab, there will not be an accessible crawl, but it is a viable plan. Any blocking in contact with the carport slab should be at least wolmanized.

[Mike Sheehan]

Footings are the first problem, most likely there is just a slab for the car port. If there is a footing, your going to have to show it to the inspector, he'll tell you what he needs.

If the old slab has a footing you can build up like you propose, but you will need a vapoer barrier to prevent moisture from coming up into the floor from the ground. You can lay a 6 mil plastic sheet down before you lay our joists, this will get torn up some during construction. There are some other products that may be a good alternate. Bituthane 4000 waterproof membrane is something I have recomended in the past.

Definatly get a permit and talk to the inspectors and plan reviewers.