|
Material World: Pressure Treated Lumber
Wood is a popular building material for
obvious reasons: high strength to weight ratio, abundance, ease of
workability, and more. However, what nature makes, nature rends asunder.
Wood’s major downfall as a construction material is that it will deteriorate
over time when exposed to the elements. Pressure treated lumber is man’s
response to nature.
Wood needs four things to rot: the right temperature, oxygen, moisture and a
food source. Anywhere wood is used that allows these elements to come
together – such as a deck, playground equipment or wood that touches
concrete or soil – would quickly decay. The process of pressure treating
seeks to eliminate the food source to prevent decay. For residential
construction use, wood is placed in a vacuum chamber and a specially
formulated waterborne chemical is introduced. The vacuum helps the wood to
draw the chemical into its substrate. This chemical prevents microorganisms
from being able to “snack” on the wood.
Pressure treated lumber is considered safe for use in residential
construction. The waterborne chemical most commonly used in residential
construction for pressure treated wood was Chromated Copper Arsenate (CCA),
but “new generation” wood preservatives have replaced CCA as of January 1,
2004. The most popular new chemicals are Alkaline Copper Quat (ACQ) and
Copper Azole (CA). Both of these chemicals have a high level of copper,
which means that special fasteners must be used. If the fasteners, flashing
or joist hangers are not galvanized, the metal can react with the copper in
the wood and cause corrosion.
Pressure treated lumber helps increase the lifespan of indoor and outdoor
structures and this leads to a more efficient use of wood resources. In the
building industry, this is another example in which man is able to improve
upon nature.
|
Thanks for stopping and visiting us in Orlando
at these 2005 Conventions
Coldwell Banker
February 10-13
Booth #200
ERA
February 14-17
Booth #200
Century 21
February 17-20
Booth #200
RE/MAX
Feb. 27 - March 2
Booth #302
|
