Download (PDF 103 KB): https://research.fs.usda.gov/download/treesearch/33204.pdf
Abstract
This paper compares average ratings of test stakes after 3, 4, 5, and 7 years exposure to their subsequent ratings after 11 years. Average ratings from over 200 treatment groups exposed in plots in southern Mississippi were compared to average ratings of a reference preservative. The analysis revealed that even perfect ratings after three years were not a reliable indicator of good performance after 11 years. Only 53% of the treatment groups with an average rating of 10.0 after 3 years had ratings at least as great as the reference preservative after 11 years. This percentage increased to 72% for treatment groups with an average rating of 10.0 after 4 years and 84% for treatment groups with an average rating of 10.0 after 5 years, and 100% for treatment groups with an average rating of 10.0 after 7 years. The data indicate that 3 years of exposure is not sufficient to evaluate a preservative intended for use in ground contact in high hazard areas, and that even slight evidence of vulnerability after 5 years may be a predictor of inadequate future performance.
Keywords
Stake tests,
ratings,
test duration,
wood preservatives,
testing,
methodology,
wood deterioration,
deterioration,
preservative treated wood,
duration,
stakes,
preservation,
treated wood,
preservatives,
copper compounds,
resistance to decay,
exposure tests,
Mississippi,
field tests,
stakes,
decay,
durability,
decomposition of wood
Citation
Lebow, Stan; Woodward, Bessie; Lebow, Patricia. 2008. Observations on the predictive value of short-term stake tests. Proceedings, 104th annual meeting of the American Wood Protection Association ... Portland, Oregon, May 18-20 2008 : volume 104. Birmingham, Ala. : American Wood Protection Association, c2008: pages 85-88.
