A.Tim Uhler, a lead framer
for Pioneer Builders in Port Orchard, Wash.,
responds: Because out-of-level foundation
walls really slow down production, I always make it
a point to check new foundations before my crew
begins framing; if there are problems, I
immediately point them out to the foundation sub
and general contractor. When the walls are more
than 1/4 inch out of level, the foundation
contractor typically should take care of the
problem, either by grinding down the high spots or
filling in the low spots.
Grinding down high spots isn’t any fun,
but filling in low spots isn’t that
difficult. One option is to use Quikrete’s
FastSet grout (800/282-5828,
quikrete.com),
a nonshrinking portland cement–based grout
that can be mixed to a fluidlike consistency,
making it a self-leveling product. If the
foundation sub can’t fix your problem,
clamp 2x4s to both sides of the top of each
out-of-level wall running the length of the
foundation, snap level lines, and pour in the grout
up to the lines. After a couple of hours, you can
set your mudsills.
If the foundation is less than 1/2 inch out of
level, we just set the mudsills normally —
first installing a foam gasket underneath the sill
— and tighten down the anchor-bolt nuts.
If the low spot is longer than the rim stock we
have available, we nail the rim together, set it
and string the top, and then shim the rim to the
line. If the low spot is localized, we just use a
piece of rim long enough to span it. Then we
install plastic or composite shims between the
mudsill and the rim joist on the joist layout,
leveling and supporting both the rim joist and
floor joists at the same time. Expanding foam
— from either a can or the insulation
sub’s spray gun — seals the
cracks between the mudsill and the rim joist.
Another option is to leave out the foam gasket
in the area that is out of level and shim between
the mudsill and the foundation (though this may not
work if the anchor bolts are set too low). Shim
every 4 feet or so to level the sill and install
shims under the ends of each joist. After the sill
is shimmed straight, use expanding foam to seal the
low spots between the concrete and the mudsill.