- Q.We‘ll be building a
house on a frost-protected shallow foundation. Are the
requirements for sizing the portion of the slab that
forms the thickened footing around the perimeter of the
slab the same as the requirements for a typical
monolithic floating slab?
A.Jay Crandell, a licensed
professional engineer and director of the
structures and materials division at the NAHB
Research Center, responds: Yes, the footing
should be sized just as required in the building
code for any footing. The key to a frost-protected
shallow foundation is simply to place the right
type and amount of insulation in the appropriate
locations to prevent frost heave from being a
problem.
For more information, consult the Design
Guide for Frost-Protected Shallow Foundations,
which is available from the NAHB Research Center
for $30 (800/638-8556; www.nahbrc.org).