framing wall on sloped floor --- where to shim?

Jul 16, 2004 11 Replies

I am finishing part of my basement. The basement floor (poured concrete) is sloped.



For instance, in one 8' section of the basement where I want to frame a wall, distance from floor to bottom of ceiling joist transitions from 76 1/2" to 75 3/4". This is due to floor sloping.



Question: Should I build the 8' wall in place with different height studs? Or should I build a square wall on the floor 1 1/2" too short (in the shortest section) and then stand the wall into place and slide in a second top plate? With this method I will need to shim the wall pretty dramatically. Even with a double top plate, there will be a gap of around 3/4" on one end. I am using 3" framing nails.



Another possibility is to build a non-square wall on the floor and again use a double top place. This is probably the easiest thing for me to do; the only awkward aspect is that the wall I be assembling on the floor will not be square. This method will not require shimming if I measure correctly.



Thanks,



michael


get some cement leveling compound, it comes in a 40 lb. bag at most hardware stores.. level the area where the bottom part of the wall is going to be and then just frame up the wall like its normal....

I built the stud wall for my entire basement in place. Nailed the top plate to the joists, concrete nail gunned the floor plate to the concrete and then measured, cut, and toe-nailed individual studs between the plates. There's just too much room for error when trying to fit floor built framing up against a wall with a top and bottom limit.

I am not an expert, and I am just trying to share my experience.

If you are going to level the floor, you may want to level the floor first before putting up the frame. Otherwise, I can see these possible shortcomings:

- If you only plan to finish part of the basement and only frame that area, you will find that framing that area first will make your task of leveling that area difficult because your back or elbows will be against the framed wall when you are trying to level the area near the framed wall.

- You may have problem nailing the baseboard trim or quarter round into the bottom framing wood in area where you have raised the floor with leveling compound or concrete. The nail can easily miss the mark. You may need to add wood block on top of the bottom framing wood as a nailer to get around with this problem.

- Leveling compound or concrete may enclose the side of some of the bottom frame. This makes the bottom framing wood to retain moisture longer than it would be otherwise (in case we have a slight moisture coming up from the basement floor), and may not allow the bottom framing wood to dry. That may or may not be a problem.

If you don't intend to level the floor, you may want to frame it in place instead of preparing the frame on the floor and raise it up. The reason is that the floor may be going up and down having many small peaks and valleys and is not in a gentle slope, and this is hard to tell if the floor has peaks and valleys without using a spring or a long piece of straight wood (I cannot tell just by my eyes). If we prepare the frame on the floor, we may find that the frame may get stuck at the bottom middle section because the floor has a small peak in that area. On the other hand, if the floor is smooth and has a gentle slope, you may be able to prepare the unsquare frame on the floor and raise it up (following one of the tip that Tom in "This Old House" suggested to prepare an unsquare frame). This is probably easier and faster this way (I haven't tried this myself).

Hope this helps.

Jay Chan

A paltry 3/4" variance over 8 ft. "dramatic"?

You haven't dealt with many old houses I'd bet!

Build it in place with every stud custom cut.

Even new houses this isn't particularly unusual.

Our previous house had everything 1" out of vertical over 8". Never noticed until I actually stuck a level on it.

Or build and erect a stud wall, sloped or not, and shim as required. It's quicker. And I _hate_ toe-nailing (toe-screwing too ;-).

3/4" isn't excessive for shimming on a non-load-bearing wall.

According to Chris Lewis :

That was supposed to be 8 _feet_, not inches ;-) I'm sure I would have noticed a 1 in 8 variation in slope. Even in my sleep ;-)

You have received all the responses. All will work. This wall only has to support the wall covering.

I would not try to level the floor.

You basically have three choices:

  1. Build in place with all that toe nailing
  2. or assuming you have room to maneuver the completed wall, build it to the height of the shortest point and shim at the top for the gaps.
  3. Or layout your top and bottom plates, marking stud locations. measure and cut each stud, nail them to the top plate in the normal manner. Secure the bottom plate and then lift the top plate and studs into position, and toenail the bottom portion of the studs.

Any of the three will work just fine if using a nail gun. Before trying number one practice toe nailing over your head with a hammer.

Have fun!

Colbyt

I wouldn't.

Did I miss something? My math came up with 3/4" difference.

I'd make the frame square. Build it...shim the one end (either wood... or fill it after the wall is up with some poured concrete).

Nor will the verticals. They'll all be at a slight angle at the floor. Not a big deal in this particular case. But not the best solution either. You want the verticals as square-fitting as possible.

Have a nice week...

Trent©

What do you call a smart blonde? A golden retriever.

Thanks for all of the helpful comments! I started building the walls in place and toe nailing as I go.

michael

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