Technical Bulletin
Metal Roof and Wall Panel Components in Contact with Preservative-Treated Lumber
The use of copper-containing preservative-treated lumber in direct contact with certain metal products could lead to accelerated corrosion and affect the long-term integrity and performance of a metal roof or wall system. The most effective way to avoid corrosion is to ensure that the treated lumber used is either manufactured using the newer metal-free preservatives, micronized copper treatment or that there is a separation between the metal roof or wall panel and the preservative treated wood with some type of barrier material.
Developments during the past several years in the preservative-treated lumber industry have led to the introduction of both metal-free preservatives and treatments utilizing dispersed or micronized copper metal. Many of these new products allow much broader contact
with other metal sheathing and connectors without the use of a barrier material. Certain specific newer treatments can even allow the use of aluminum products without a barrier.
