Abstract
The pre-test moisture content and conditioning history of wafers cut from wood treated with CCA and an emulsion water repellent additive can dramatically influence swelling curves generated using a standard swellometer apparatus. The rate of water uptake and swelling increased significantly as wafers were dried to lower moisture contents prior to immersion swelling. The pre-swelling conditioning history can also influence swellometer curves and confuse the interpretation of relative water repellent efficacy of emulsion water repellent systems. Results support that careful pre-conditioning of wafers is critical for meaningful comparisons of the relative efficacy of water repellent emulsion systems.