Quality In Treated Wood Products
Hart Brand Pressure Treated Wood Products have been subjected to high quality standards for nearly 40 years. Since 1990 we have invested in a quality assurance program. Inspectors regularly subject all of our treated products to laboratory analysis and reject for shipment any material that fails to meet quality of treatment standards set by the American Wood Preservers Association (AWPA). An agency is also qualified to inspect and approve treated products for use on state, federal and municipal projects.
Quality of Treatment is based on 2 factors:
1) Depth of penetration
2) Concentration of the preservative chemical
Item #2 is known as retention and is commonly listed in tenths of pounds per cubic foot of wood.
Before a core sample of treated material is analyzed for retention, it must first meet or exceed the criteria for depth of penetration.
AWPA Standard C-S Fencepost requires depth of 2 inches or 85% of the sapwood, or treatable portion of the wood.
Because they are either fully seasoned or kiln dried prior to treatment, the absence of water in the wood means that Hart Brand products regularly meet or exceed the penetration standard. The heavier, darker oil component of the treating solution tends to penetrate the outer growth rings, while the lighter oils continue to migrate toward the heartwood for up to six weeks after treatment.
Once the inspector is assured that depth of penetration is acceptable he proceeds to perform a lab analysis on the core samples to determine retention.
The preservative treatment used in Hart Brand products is Pentachlorophenol dissolved in oil. Penta is the preservative chemical and oil is the carrier with which the preservative is pressed into the wood. We feel that Penta in Oil is the superior treatment for commercial and farm use, as opposed to water borne preservative treatments, because the oil itself imparts durability characteristics to the finished product.
Hart Brand retention figures are listed in tenths of pounds of pure Penta per cubic foot of wood.
The AWPA standard requires .4 pounds per cubic foot.
Since 1990, Hart Brand retention figures have exceeded the standard by approximately 15%.
Without regular and qualified inspection and analysis, it is impossible to judge quality of treatment in wood products. You will discover many facts, figures, and standards recklessly thrown around the marketplace, and it is critical that the purchaser of treated wood products understands what defines quality and how it is measured.