Performance of Northeastern United States wood species treated with copper based preservatives: 10 year above-ground decking evaluation

Abstract

Research was conducted to evaluate the decking performance of northeastern United States wood species treated with copper based preservatives. Decking specimens were treated with one of four wood preservatives and exposed near Madison, Wisconsin. Specimens were evaluated for biological attack and dimensional stability. After 10 years, none of the preservative treated specimens had fungal decay. All of the untreated Southern Pine specimens were severely decayed within 5 years, but untreated specimens of other species were much slower to decay. Surface mold was most commonly observed on untreated specimens, but was also sometimes present on preservative treated wood. Warp and checking were greatest in red maple and least in eastern white pine. Although all wood species/preservative combinations were decay resistant, concerns with appearance and dimensional stability may make red maple and balsam fir less desirable for use as decking. Eastern white pine appears to be the northeastern species most suitable for use in decking.