This project evaluated the effect of treatment time on chemical penetration and retention of copper sulfate and sodium fluoride in wood treated using the double diffusion process. Two treatment trials were conducted. Trial 1 utilized eight-foot ponderosa pine 4x4s. Trial 2 utilized two-foot sections of end sealed lodgepole pine posts. Copper retentions in all Treatment Schedules in Trial 2 were higher than required by AWPA for CCA treated wood rated for ground contact. Fluoride retentions did not meet published threshold levels for number of fungi.
