Documenting the Durability and Service Life of Pressure-treated Wood

Preservative treatments can greatly extend the useful life of wood products. Estimates of expected service life are commonly used to compare long-term life-cycle costs for a variety of building materials. Quantifying the expected increase in service-life for treated wood is a challenge few have undertaken. Until now.

From left to right are examples of different treated wood: micronized copper quaternary (MCQ), didecyldimethylammonium carbonate (DDAC), and alkaline copper quaternary (ACQ-D). Cupric ions from the wood preservative causes the dark coloration of the wood. Excess copper has deposited on the MCQ (green splotches) and the ACQ (along the end grain).

Three types of treated wood, from left to right: micronized copper quaternary (MCQ), didecyldimethylammonium carbonate (DDAC), and alkaline copper quaternary (ACQ-D).

An interdisciplinary team of FPL researchers have worked to make additional treated wood service life information available to engineers and others interested in comparing construction material costs and service life expectations. Forest products technologist Stan Lebow, microbiologist Bessie Woodward, and statistician Patricia Lebow presented their work at the 108th Annual Meeting of the American Wood Protection Association in 2012. It is now available as a free download.

Existing service-life data and reports may eventually be summarized and published in formats that are readily accessible and easily understood. Life cycle cost analysis (also known as LCCA) is increasingly common for projects receiving federal funding, particularly for critical transportation structures such as bridges. Life cycle assessments are becoming a key part of evaluating potential environmental, economic and social impacts derived from various building materials and processes.