Water-borne preservative marine trials in Western Canada
J N R Ruddick
Red pine boards treated with chromated copper arsenate, ammoniacal copper arsenate, copper zinc arsenic additive, a modified ammoniacal copper arsenate, and zinc arsenic additive, have been installed in a marine field test at West Vancouver, British Columbia. After two and a quarter years exposure, all the test samples are in excellent condition with the exception of those treated with the zinc arsenic additive. All the zinc arsenic additive treated boards at the lowest preservative retention and two thirds of those at the second lowest retention in test have failed. A performance index calculated for the zinc arsenic additive indicates an added service life of 3% at the standard retention level.