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Southern Pine's ease of treatability has made it the preferred species
when pressure treatment with wood preservatives is required. The unique
cellular structure of Southern Pine permits deep, uniform penetration of
preservatives, rendering the wood useless as a food source for fungi, termites
and micro-organisms. Some 85% of all pressure-treated wood is
Southern Pine, a general group of four tree species: shortleaf, longleaf,
loblolly, and slash. Collectively, this species group ranks among the
strongest, most versatile wood for structural applications.
Most untreated wood will decompose when four conditions required for
decay and insect attack occur: high moisture, a favorable temperature, oxygen,
and a food source (wood fiber). If any one of these conditions is
removed, infestation and decomposition cannot occur. Eliminating wood
fiber as a food source by using pressure-treated wood products is an easy
solution. Research shows that wood can be expected to last for many
decades when properly treated and installed for its intended use.1
Figure 1 indicates, by region, the level of wood deterioration throughout
the United States. Because deterioration zones range from moderate to
severe across most of the country, today's design/build professionals realize
the importance of specifying and building with treated wood.
Modern science has developed preservative treatments that are odorless
and colorless, and leave the wood paintable and dry to the touch. Treatment
with preservatives protects wood that is exposed to the elements, in contact
with the ground, or subjected to high humidity.
Not all wood treats the same. Most wood species do not readily accept
preservatives, and must first be "incised" or perforated with slits along the
wood's surface in accordance with American Wood Protection Association
(AWPA) standards. Because of its superior treatability, Southern Pine is one
of the few wood species that does not require incising.
Pressure-treated wood is safe and environmentally friendly when properly
treated, handled, and installed:
- Proper handling and use of treated wood poses no increased risk to human or
animal health.
- Wood preservatives do not aggressively leach into the ground or waterways,
drinking water supplies, or adversely affect marine life.
- Wood products last much longer with pressure treatment, which helps conserve
a valuable, renewable natural resource — our trees.
- Alternative products such as plastic composites, require more energy to produce,
and may also be aesthetically unacceptable to consumers.
Many of the same safety rules for using untreated wood also apply to the safe
use of treated wood. See Consumer Use and Handling Guidance.
(1) "Comparison of Wood Preservatives in Stake Tests — 2000 Progress Report," Forest Products Laboratory; Research Note FPL-RN-02; U.S. Department of Agriculture
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