Laboratory Decay Resistance of Preservative-Treated Red Alder

Alder represents an abundant but underutilized resource that has little natural resistance to decay. Treated alder might be used for stakes, posts, or other nonstructural applications. The performance of alder treated with chromated copper arsenate (CCA), copper 8 quinolinolate, zinc naphthenate (ZN), or thiocyanomethylthiobenzothiazole (TCMTB) was assessed in soil block tests. CCA provided the best protection, and ZN and TCMTB provided reasonably good protection. Copper 8 required loadings of at least 6 kg/m3 to provide protection