treemaker

I recently purchased a townhome (built 2003) and after a few weeks I noticed a slope in the floor perpendicular to the joists. I am sure the slope was there before, but I never noticed it. We have laminate floors, so it is maybe a bit more visible than with carpet. It occurs over about 36" and then the floor is level again, but a tiny bit lower than the rest. It is almost as though the tops of the joists are higher over most of the floor and then are a bit lower toward one end.

We had the home inspected and the foundation checked out -- no major cracks and the joist span is short with no sagging. I have also gone into the crawl space and the only thing I noticed is that the 2 x 10 joists are slighty shorter in the vertical in the area with the issue (by about 1/4 inch). Is it possible that the tops of the joists are not level? Since it is perpendicular to the joists, I am puzzled.

Thanks,
Graeme

glennjanie

Welcome to the Forum, Graeme:
Yes, it is possible the tops of the joists are uneven and, to cure it, you could go under the floor (with a helper and straight edge above) and shim under the joists in question to the level of the others.
You will probably have to pull the nails out of that end of the joists while you do the shimming, and re-nail them when you are happy with the height.
Glenn

treemaker

Thanks. We are thinking about putting some new floors in, so it would be a good opportunity then.

What is the best way to shim the joists & what is the best material for that job?

Thanks,
Graeme

glennjanie

Hey Graeme:
It depends on how your joists are attached. If they are in metal joist hangers, you could shim under the joists at the bottom of the hanger. If you have a 2 X 2 ledger at the bottom of the beam you could shim from that. The problem occours in a 36" space, which should involve only 2 joists. Another method would be to pull all the nails and use a flat pry bar in the saddle of the joist hanger or against the nail ledger.
One more shot: Crib up under the affected joists, pull the nails out of them, use shims on the crib stack to raise the joists and re-nail them. The easiest way to re-nail the joists is with metal joist hangers. The cribing may be concrete blocks, 4 X 4 or 4 X 6 timbers, or even a couple of auto jack stands placed on a 2' square of plywood (one under each joist).