An accelerated decay test was set up to compare the performance of CCA-treated western spruce and lodgepole pine lumber treated to various depths of preservative penetration. Short lengths of treated 2 x 4s and comparable untreated material were installed in a soil bed. After ten years of exposure, the CCA treatments were still sound, while the untreated material had failed due to decay. Deterioration of the central untreated zone on the buried end of some material was caused by failure of the field-cut preservative, not the CCA treatment.
Preservatives - Tests - Soil block
Picea - Preservation
Pinus contorta Dougl. var. latifolia - Preservation