Framing and Sub-Flooring - Framing a door over uneven floor

I'm not a carpenter, but I usually can figure out handyman problems given enough time. This one has me stumped.

I'm helping my son convert a 1940s-era free-standing garage into a studio. We need to frame in a bay entrance that never had a door on it. He wants to put a prehung, fiberglass exterior door and window into this new framed wall we will construct. The problem is, the concrete floor is slightly off-level.


Are there any tricks for getting this to work short of pouring a new, level slab over the old one (not in the budget)?
Assuming there's a fix for the above, can the sill go directly on the concrete?


Thanks very much.

angus

Angus, just how out of level is it? 1/4" in 3'?

Angus, just how out of level is it? 1/4" in 3'?

Chandler, I put a 4' level on it yesterday and it looked like it was out about 3/8" on the side he'd like to put the door. The floor is actually slightly cupped (I'm sure we'll have to custom-fit each stud) and it's possible to get a level reading across the middle with a small gap underneath. But he's trying to maximize wall space inside and prefers to have the door on the side.

I was wondering if shimming it to plumb and injecting some sort of filler under the metal threshhold would work?

Thanks!

angus

(Hey, I was in Young Harris a few months ago for the first time. Beautiful area!)

We spent a lot of time looking this problem over yesterday.

The treated sill would be about 6 feet long and have up to a 3/4" gap along the last foot at the end where it would butt against the door jamb. Otherwise, it makes solid contact with the floor along the rest of it's length and is close to level. The door, itself, stands almost perfectly plumb.

I'm wondering if we could "shim" that gap with cement board, hold it all in place with anchor bolts and construction adhesive and fill the gaps with foam or self-leveling concrete?

I've been told that using self leveling concrete to create new bed for the entire sill is not a good idea because it will crack if it gets wet and freezes.

Any other thoughts?

Angus, sorry for the delay, you know, leaves changing color and such. Glad you enjoyed our area, and return sometime!
Being on an exterior wall, using the self leveler over the whole floor probably would crack with the changes in the wx. You may have good success in using cbu under the threshold as far as it would go, shimming it as necessary with pt or plastic shims, than filling the gap with silicone (foam won't stop water infiltration). Just make sure you have good support across the entire width.

Thanks, again, Chandler. I'll give this a try. Good luck with those leaves!

angus

Oh chandler isn't raking them I bet...he just likes looking at them!

This may be another option....instead of a self leveler...you might use a concrete resurfacer....http://www.quikrete.com/ProductLines/ConcreteResurfacer.asp

http://www.quikrete.com/images/Products/prod_1131.jpg

Or maybe something like sand mix?

http://www.quikrete.com/images/Products/prod_1103.gif

That will insure it is completely filled and supported.

You'll laugh, but all our leaves seem to blow against the east fence. All I have to do is put the mulching plate on the ztr and make swipes. Done.