PRESSURE-TREATED
LUMBER:
 Southern
Pine is a general group of four principal tree species:
long-leaf, shortleaf, slash, and loblolly. Collectively,
this species group ranks among the strongest, most
versatile woods for structural applications.
When most wood is exposed to
the elements, excessive moisture, or contact with the
ground, it will decompose. That is because four conditions
are required for decay and insect attack to occur:
moisture, a favorable temperature (approximately 50
to 90 degrees Fahrenheit), is removed, infestation
and decomposition will
not occur. Chemical preservatives eliminate wood fiber
as a food source. Why design and build with pressure-treated
wood? Figure 1 indicates, by region, the level of wood
deterioration throughout the United Stats. As shown,
deterioration zones ranging from moderate to severe
cover most of the country.
 Modern
science has developed preservative treatments that
are odorless and colorless, and leave the wood paintable
and dry to the touch. Treatment with chemical preservatives
protects wood that is exposed to the elements, is in
contact with the ground, or is used in areas of high
humidity.
Southern Pine has long been a
preferred species when pressure treatment with preservatives
is required, because of its ease of treatability. The
unique cellular structure of Southern Pine permits
deep, uniform penetration of preservative chemicals,
rendering the wood useless as a food source for fungi,
termites and micro-organisms. Some 85% of all pressure-treated
wood is Southern Pine.
However, be aware that all treated
wood is not created equal. Most wood species do not
readily accept chemical preservatives, and must first
be "incised" or perforated with a series of small slits
along the grain of the wood's surface. Incising allows
sufficient penetration of the preservative to meet
American Wood Preserver's Association (AWPA) Standards.
Southern Pine is one of the few wood species that does
no require incising.
In addition, the use of treated
Southern Pine products poses no measurable risk to
humans, animals, plant or marine life.
Scientific research studies have
shown the following:
• Preservatively treated wood products last longer than alternative materials,
conserving a renewable, natural resource.
• Wood preservatives do not aggressively leach into the ground or waterways,
drinking water supplies, or adversely affect marine life.
• Proper handling and use of treated wood poses no increased risk of cancer
or other illnesses among human, animal, and marine life.
• Preservatively treated wood products have been extensively tested and
proven to be more reliable and durable than alternative products which require
more energy to produce, and may also be aesthetically unacceptable to consumers.
How long does pressure-treated
wood last? Currently available research shows that
wood that has been properly treated and installed for
its intended use can be expected to last for many decades.
Ongoing tests sponsored and monitored
by the USDA forest Service's Forest Products Laboratory
confirm this finding. Test stakes of treated wood have
been buried in the ground at various locations, stretching
from the Mississippi Delta to the Canadian border.
Data analysis indicated that CCA-treated Southern Pine
stakes in place since 1938 have shown no failures at
chemical retention levels of 0.29 pounds of preservative
per cubic foot of wood, or higher. 1
(1) "Comparison of Wood Preservatives
in Stake Tests - 1995 Progress Report", Forest Products
Laboratory; Research Note FPL-RN-02; U.S. Department
of Agriculture
Article courtesy of Southern
Pine
If you'd like to learn more about SFPA,
visit our web sites at
www.sfpa.org/
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