Naturally-durable wood species are offered as an alternative to chemically-treated wood for decking and siding. Restrictions on imports due to non-sustainable forest practices often limit the availability of tropical hardwoods, many of which are considered durable. The Forest Products Laboratory is evaluating native naturally-durable woods for use in covered bridge repair and rehabilitation in conjunction with the Federal Highway Administration to provide native alternatives to tropical hardwoods. Six wood species that are considered either invasive or underutilized were selected for both above ground and inground exposure in Madison, WI. Western red cedar (WRC), Alaskan yellow cedar (AYC) and untreated southern pine (SYP) were also included for comparison. Eastern red cedar (ERC), black locust (BL), honey mesquite (HM), and AYC are all still remaining durable in ground contact while Catalpa (CAT), WRC, SYP, and Paulownia (PAW) have failed. Data from both inground and above ground eight-year exposure in WI are presented herein and discussed.
underutilized wood species
Kirker, Grant; Bishell, Amy; Lebow, Stan. 2018. Above and in-ground performance of naturally-durable woods in Wisconsin. In: McCown, C.; Branton, K., eds. Proceedings, One hundred fourteenth annual meeting, American wood protection association. Birmingham, AL: American Wood Protection Association: 272-277.