Pressure-treated lumber is as its name says: treated with chemicals and put in a pressure chamber. The North American Deck and Railing Association (NADRA) stated millions of wood decks in the U.S. use pressure-treated lumber due to its resistance against natural hazards. Both the deck designer and builder agree that this type of wood is the way to go.
Wood, basically, is an exceptional product for building and remodeling, specifically if you desire a house to have a natural appearance. The only concern is that it's prone (and delectable) to virtually every known bug and bacterium on the planet. When the wood sustains damages as a result of termites and the like feeding on it, the entire structure would break down. This is why a deck designer often suggests building decks with pressure-treated wood.
In a nutshell, pressure treatment means making the wood less tasty for termites and the like. Makers treat wood with chemical preservatives like alkaline copper quat (ACQ) to safeguard the wood from insect and bacterial attacks. The preservatives also help extend the life expectancy of the deck, a big must for outdoor decks.
In the past, chromated copper arsenate (CCA) was utilized as the prime chemical for this procedure. However, in 2003, the Environmental Protection Agency (EPA) restricted the use of CCA due to the presence of the hazardous arsenic, which can taint natural resources. In addition, the preservative will have to be accredited by the EPA for usage in household and commercial settings.
By exposing the treated wood to a certain amount of pressure, the chemicals can seep into the wood deep down for optimum defense. In the initial stage, the treated wood is exposed to pressure of 35 to 40 psi. For the next three hours of the process, the pressure is raised to 140 to 150 psi for the chemical to permeate into the wood. In the final step, the excess preservative is removed, and the pressure is lowered.
You can discover more about the fundamentals of pressure-treated wood by reviewing the report courtesy of the Oklahoma State University on OKState.edu. You could also check out NADRA.org, the official website of NADRA for additional details. Another good resource is your local deck builder.
Deck Designer Ideas: Pressure-Treated Wood for Outdoor Decks