Manufacture

Timber piles are a natural, home-grown product. Trees are harvested from the forest, usually from managed timber plantations, and delivered for processing. The first step in the process is removal of the bark. The bark is mechanically removed down to white wood. The tree is then inspected to ensure it meets the requirements of ASTM D-25, Standard Specification for Round Timber Piles. ASTM D-25 defines the standards that timber piles must meet for straightness, size and density. After debarking, the piles are sorted by class and length.

The next step in the process is pressure treatment. Chemical preservatives are forced deep into the cellular structure in a closed, pressurized cylinder This pressure enables the preserved wood to maintain a chemical barrier against termites, decay, and marine borers. The AWPA has developed standards for the proper preservative as well as the penetration and retention for the preservative in the various species of timber. These standards ensure that the proper amount of preservative is used for specific applications and provide for consistent quality in the timber.

The first step in the treatment process is to dry the timber. The timber is placed in a large kiln where heat and moisture are regulated to safely and efficiently prepare the timber for preservative treatment.

Once the timber is prepared, it is placed in a cylinder where preservative treatment is forced into the cells of the timber under pressure. This creates a protective envelope around each piece of timber. After the preservative treatment has been applied, tests are conducted to ensure that the specified retention and penetration requirements have been met. When the preservative treatment operation has been satisfactorily completed, the piles are ready for installation.