Wood preservatives. Method for natural preconditioning out of ground contact of treated wood specimens prior to biological laboratory test

Major changes are taking place in the residential decking market driven by concerns over wood preservatives and the resulting phase-out of chromated copper arsenic (CCA)-treated wood and recent entry into the marketplace by wood-plastic composites. Using conjoint analysis, this study explores consumer perceptions regarding residential decking materials over two time periods, 2000 and 2003. Type of material and lifetime were the most important decking attributes. Of lesser importance were annual maintenance and price. Major changes took place over the three-year study period with respect to opinions towards treated wood and wood-plastic composites. Consumers became much more negative towards treated wood and wood-plastic composites received nearly equivalent gains. The CCA controversy clearly had an impact in the marketplace and we demonstrate the usefulness of conjoint analysis in capturing this change. Key words: decking, consumer, conjoint analysis, plastic lumber, treated wood, cedar, substitution

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Effect of Concrete on the pH and Susceptibility of Treated Pine to Decay by Brown-Rot Fungi

Forests ◽

10.3390/f11010041 ◽

2019 ◽

Vol 11 (1) ◽

pp. 41 ◽

Cited By ~ 2

Author(s):

Darrel Nicholas ◽

Amy Rowlen ◽

David Milsted

Keyword(s):

Treated Wood ◽

Untreated Wood ◽

Brown Rot ◽

Consistent Difference ◽

Ground Contact ◽

Decay Fungi ◽

Brown Rot Fungi ◽

Organic Systems ◽

Decay Tests ◽

Copper Azole

Treated wood timbers employed in ground contact are often installed with a cement collar to firmly fix the structural wood post in place. Few prior studies have determined the effect of concrete on decay efficacy on treated wood, however. Treated wood nominal 4 × 4 posts were installed at four locations, with the upper ground-contact portion of each post encased in concrete, and the samples removed at various times for pH measurements. The wood alkalinity quickly increased at all four sites for the portion of the treated wood in concrete contact compared to the wood in ground contact without concrete. In laboratory decay tests employing three decay fungi, untreated wood which was first exposed or unexposed to concrete had no consistent difference in decay susceptibility. For wood treated with three different commercial copper/organic systems, cement exposure had no effect on wood treated with an amine copper azole system, while treatment with amine copper quat showed a statistically significant fungal efficacy enhancement for cement-exposed samples with both copper-tolerant fungi. Conversely, with a micronized copper azole preservative, cement exposure resulted in reduced fungal efficacy compared to treated samples which were not cement-exposed for all three decay fungi.

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