The Virginia Uniform Statewide Building Code (USBS) requires
“localities with 20% or greater moderate and high
shrink/swell potential of jurisdictional land area” to
implement an expansive soil testing policy. Fauquier County
is included on the list of localities with 20% and greater
moderate and high shrink/swell potential.
The intent of the expansive soil testing policy is to
prevent damage to homes due to the presence of expansive
clays. Expansive clays are certain clay minerals that
markedly change volume with changes in moisture content. The
increase in volume with increasing water content exerts
extremely high pressures. These volume changes and pressures
can damage or destroy homes.
Areas with expansive clays have already been identified by
the Fauquier County Soil Survey. The soil maps will be used,
prior to issuance of a building permit, to determine if the
house is going to be constructed in an area of moderate or
higher shrink – swell potential. If so, the owner will be
required to have a certified professional take soil samples
from the area where the foundation is to be constructed. The
samples will be submitted to a soils laboratory for
appropriate testing (see attached policy for the test the
Unified Statewide Building Code identified as appropriate).
The resulting data will be provided to a certified
professional who will use it to design a foundation that
will withstand the changes in volume and pressures of the
expansive clays on that site. While the owner will have to
bare the cost of the sampling and testing, approximately
$300 to $600, the test potentially can save an owner
thousands of dollars in repairs and reconstruction that
would be required if an inadequate foundation is installed.
It is not clear that the law requires a public hearing or a
Planning Commission recommendation to the Board of
Supervisors. However, because the adoption of the expansive
soil testing policy will place new costs and burdens on the
public, staff recommends the deliberate process of notice,
hearing, and Planning Commission recommendation. This matter
was initiated by the Planning Commission on June 30, 2005.
On July 28, 2005, the Planning Commission held a public
hearing on the adoption of this policy and then recommended
it favorably to the Board of Supervisors.