Tricky Details
by Gordon F. Tully
Stepped Footings
Don't step the bottom of a footing
unless you construct the step in two
pours (see diagram). Each type of soil
has a natural "angle of repose."
When you dig down, any soil inside
the angle of repose will loosen or
collapse. If a footing needs to step
The options are to use taller forms,
add blocking to the top of the forms,
or increase the thickness of the sill to
6 or 8 inches (see diagram).
Using a 6- or 8-inch-deep sill has a
minor advantage in houses where the
first-floor joists sit on a wood
carrying beam. With a standard 2-
up, its bottom should rise along the
angle