A large part of my business as a foundation
contractor in northern California
is replacing foundations. Many of
these foundations are intact, but are
built of unreinforced masonry that is
inadequate to support future loads
from expected earthquakes or a major
renovation. The foundation may
already show signs of distress, whether
it is from seismic activity or just bad
drainage. This distress often shows up
when siding is pushed out of plumb
and cripple-wall studs no longer bear
on the concrete, because the foundation
has "rolled" (Figure 1, next page).
In other cases, a grade beam may be
cracked into separate pieces in several
locations. Such problems justify the
replacement of the distressed section
of foundation. In this article