A Laboratory Soil-Contact Decay Test: An Accelerated Method To Determine Durability of Treated Wood Shakes
Keywords:preservative, method, shake, roofing, hemlock, pine, alder, wood decay, durability
AbstractIn this study, cross sections of preservative-treated shakes were evaluated in soil-contact decay tests using Gleophyllum trabeum. The number of preservatives by species combinations used allowed evaluation of procedural aspects of this method. We conclude that the soil-contact decay test is a good tool for an accelerated evaluation of the durability of treated shakes. Experimental designs need to be structured so that each wood species can be analyzed separately. Interpretation of results requires consideration of both the distribution and median or mean of weight loss data for each treatment. Levels of retention should be well dispersed so that the effects of retention upon distribution of weight loss data for individual treatments can be determined. Selection of a sufficient sample size to represent the variation within the population of each wood species by treatment combination is judged to be more important than duration of the incubation period in excess of 12 weeks. Stated differently, a rigorous experimental design permits discrimination of major differences without a need to achieve a weight loss of 50% in untreated materials. Wood species utilized in this study were western hemlock (Tsuga heterophylla (Raf.) Sarg.), Pacific silver fir (Abies amabilis Dougl. ex Forbes), grand fir (Abies grandis Dougl. ex D. Don Lindl.), western white pine (Pinus monticola Dougl. ex D. Don), southern pine spp., and red alder (Alnus rubra Bong.).
American Society For Testing and Materials. (Astm). 1986a. D1413-76 (reapproved 1986) Standard method of testing wood preservatives by laboratory soil block cultures. Annual Book of Standards. ASTM, Philadelphia, PA.nAmerican Society For Testing and Materials. (Astm). 1986b. D2017-76 (reapproved 1986) Standard method of accelerated laboratory test of natural decay resistance of woods. Annual Book of Standards. ASTM., Philadelphia, PA.nAmerican Wood-preservers' Association (Awpa). 1989. A12-89 Wood densities for preservative retention calculations by standards A2, A9; and A11. Book of Standards. AWPA, Stevensville, MD.nBarnes, H. M., B. Buchanan, and T. L. Amburgey. 1985. Treatment and durability of wooden roofing materials. Proc. Am. Wood-Preserv. Assoc. 81:89-108.nBergervoet, A. J. 1984. A method for treating partially seasoned pine with CCA preservatives. Proc. Am. Wood-Preserv. Assoc. 80:90-96.nDe Groot, R. C. 1994a. Comparison of laboratory and field methods to evaluate durability of preservative-treated shakes. Wood Fiber Sci. 26(3):309-314.nDe Groot, R. C. 1994b. Treatability of western softwoods and red alder shakes. Forest Prod. J. 44(7/8):34-43.nDe Groot, R. C. 1994c. Field trials with preservative-treated shakes in southern Mississippi. Proc. Am. Wood-Preserv. Assoc. 90:88-105.nDuncan, C. G. 1957. Evaluating wood preservatives by soil-block tests: 9. Influence of different boiling fractions of the petroleum carrier on the effectiveness of pentachlorophenol and copper naphthenate. Proc. Am. Wood-Preserv. Assoc. 53:13-20.nForest Products Laboratory. 1987. Wood handbook: Wood as an engineering material. USDA Agric. Handbook 72. rev. Washington, DC: 466 pp.nGovett, R. L., R. De Groot, R. L. Folk, and T. M. Gorman. 1991. Grand fir and dead western white pine as potential substitutes for western red cedar in the manufacture of tapersawn shingles. Forest Prod. J. 41:21-26.nMitchoff, M. E., and J. J. Morrell. 1988. Laboratory decay resistance of preservative-treated red alder. Wood Fiber Sci. 20:370-377.nRudman, P., L. Henderson, D. F. Mccarthy, and E. A. Bowers. 1963. The impregnation of green Pinus radiata D. Don with an unfixed water-borne preservative by steam-vacuum drying and intermittent pressure treatment. J. Inst. Wood Sci. 11:45-56.nSas Institute, Inc. 1994. Sas version 7. Cary, NC.nVelleman, P. F. 1989. Data desk. Copyright Data Description, Inc., Ithaca, NY. Published by Odesta Corp., Northbrook, IL.nWard, H. A. United States Patent 4, 950,685. August 21, 1990.nWilcox, Wayne, W. 1980. Bioassay to determine penetration and efficacy of a wood preservative applied by soak treatment. Forest Prod J. 30:55-57.n
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