Comparison Of Laboratory And Field Methods To Evaluate Durability Of Preservative-Treated Shakes

Authors

  • Rodney C. De Groot

Keywords:

Preservative, shakes, wood decay

Abstract

Environmental concerns and life-cycle requirements of treated wood products require methods that define the minimum amount of preservative that will be needed to protect products in use. This study illustrates the relative merits of three methods that are used to evaluate the durability of treated wood shakes. Severity of challenge from decay fungi is greatest in laboratory soil jar methodology, next greatest is in field modules composed of stacked shakes, and least is in shakes exposed on small sections of roof decks in the field. Small sections of roof decks allow assessment of stability, color, and other weathering characteristics. Modules of stacked shakes allow opportunities to design field experiments to evaluate effectiveness of preservatives with a test unit that is conducive to decay.

References

ASTM. 1986. Standard method of testing wood preservatives by laboratory soil block cultures. D 1413-76 (reapproved 1986) Annual Book of Standards. American Society of Testing and Materials, Philadelphia, PA.nASTM. 1989. Annual book of standards (various standards). American Society of Testing and Materials, Philadelphia, PA.nAWPA. 1991. Al 1-83. Standard method for analysis of treated wood and treating solutions by atomic absorption and spectroscopy. Book of standards. American Wood-Preservers' Association. American Wood-Preservers' Association, Woodstock, MD.nASTM. 1992a. A12-89. Wood densities for preservative retention calculations by standards A2, A9, and All. Book of standards. American Wood-Preservers' Association. American Wood-Preservers' Association, Woodstock, MD.nASTM. 1992b. El 0-91. Standard method of testing wood preservatives by laboratory soil-block cultures in Book of standards. American Wood-Preservers' Association. American Wood-Preservers' Association, Woodstock, MD. 11 pp.nASTM. Report of Subcommittee P-5. Method for chemical analysis of preservatives. Pages 273-338 in Proceedings 1993 American Wood-Preservers' Association. American Wood-Preservers' Association, Woodstock, MD (in press).nBarnes, H. M., B. Buchanan, and T. L. Amburgey. 1985. Treatment and durability of wooden roofing materials. In Proceedings, American Wood-Preservers' Association 81:89-108. Reno, NV.nDe Groot, R. C. 1992. Test assemblies monitoring decay in wood exposed above ground. Int!. Biodeter. Biodegrad. 29:151-175.nDe Groot, R. C. [in preparation]. Treatability of western softwood and red alder shakes.nForest Products Laboratory. 1987. Wood handbook: Wood as an engineering material. Agric. Handbook 72. USDA, Washington, DC. 466 pp.nPreston, A. F. 1983. Dialkyldimethylammonium halides as wood preservatives. JAOCS 60(3):567-570.nPreston, A. F., and D. D. Nicholas. 1982. Efficacy of a series of alkylammonium compounds against wood decay. Wood Fiber 14(1):37-42.nRoddick, J. N. R. 1986. The influence of staining fungi on the decay resistance of wood treated with alkyldi-methylbenzylammonium chloride. Mater. Org. 21(2): 139-149.nScheffer, T. C. 1971. A climate index for estimating potential for decay in wood structures above ground. Forest. Prod. J. 21(10):25-31.nTsunoda, K., and K. Nishimoto. 1987. Effectiveness of alkylammonium compounds as above-ground wood preservatives. Mokuzai Gakkaishi 33(7):589-595.nWard, H. A. 1990. U.S. patent 4,950,685. August 21.nWilcox, W. Wayne. 1980. Bioassay to determine penetration and efficacy of a wood preservative applied by soak treatment. Forest Prod. J. 30:55-57.n

Downloads

Published

2007-06-25

Issue

Section

Research Contributions