Optimum protection against Formosan termites is attained
by using all pressure-treated Southern Pine kiln-dried
after treatment (KDAT) lumber and sheathing for this 14,000
square-foot lakefront home in suburban New Orleans.
Question: "If I lived in an area where termites are a problem like much of the
Southeastern U.S., won't my raised wood floor system be more
vulnerable to attack than a comparable concrete slab-on-grade
constructed home?" The short answer is NO!
The question is understandable, since termites consume wood, or more
specifically any cellulose material (paper, cardboard, or solid
wood). The truth is, a home constructed on a concrete slab is just
as vulnerable, if not more so, to termite infestation than a
comparable home properly constructed on a raised floor.
Subterranean termites are ground dwellers. They rely on ground
moisture to survive and thrive. Concrete slab-on-ground foundations
rest directly on the damp earth, giving termites a very short
commute from their natural habitat to house framing. In addition,
slabs often crack, offering termites a virtually undetectable
entryway into the house.
On the other hand, a raised floor elevates the structure above the
ground, isolated from the moisture source, and away from termite
habitat. The raised floor system makes termite detection simple for
trained pest control exterminators who can easily inspect underfloor
areas.
Treated Framing Adds Value and Protection for Minimal Cost
Finally, if concerns exist over vulnerability to pests, the
raised floor system — or even the entire house — can
be framed with pressure-treated Southern Pine lumber, structural
panels, and other engineered wood components. The "whole house"
concept of using pressure-treated wood framing components in
high-moisture areas of the home for added protection against
decay and termite attack is nothing new.
Informed builders and homeowners have used pressure-treated lumber
for optimum protection of structural framing members. In fact,
analysis by the Louisiana Department of Agriculture and Forestry
indicates that a typical home (about 2,000 square feet) could be
framed entirely with pressure-treated components, while adding about
2% to the overall cost of the home¹.
A typical home framed entirely with pressure treated wood
adds about 2% to the cost of the home1.
Widespread damage by the Formosan termite has put considerably
more emphasis on the use of pressure-treated framing, whether
in the raised floor system or for the entire framing of the
home. The American Wood-Preservers' Association has approved
several preservative treatments effective against Formosan termites
that are suitable for residential or commercial enclosed (interior)
framing applications; see Table
4 and Table 5.
Soil Treatment
Termite Shield
For all structural framing uses, pressure-treated lumber must
be dried after treatment to a moisture content of 19% or less.
To learn more, see Termite-Resistant
Structures.
The use of pressure-treated wood offers homeowners the most
practical, cost-effective and safest way to fully protect framing
components from termites or fungal decay.
After removal of all scrap wood from the building perimeter,
treatment of the soil around the foundation with an approved
termiticide is an effective protection against subterranean termites.
Properly installed termite shields also provide effective protection.
Regular inspection and termite treatment is recommended. Termite
shields may be required in certain localities by the building code.
