What experience has Simpson had with the alternative treatments that are replacing CCA-C?
Simpson first became aware of some CCA-C alternatives being used when we received reports of increased connector and fastener corrosion when installed with some treated woods. These reports led us to explore the phenomena and expand our corrosion warning in our catalog to include specific language related to treated wood. As time progressed and the public concern over the safety of CCA-C intensified, the treated wood industry decided to voluntarily phase out CCA-C. Simpson has tested more than 1,800 samples of various combinations of steels, coatings, preservative treatments, wood species, and over 3,000 fasteners to try to better understand the issues. Using the American Wood-Preservers Association test standard E12-94 for many of these tests, our results indicate there are some significant differences between the corrosion rates of CCA-C and some of the “alternative” products. The E12-94 test standard is an accelerated test method. The test results may or may not have a relation to a
