What is the difference between Exterior and Exposure 1?
Exterior panels have a fully waterproof bond and are designed for applications subject to exposure to the weather or to moisture for its entire service life. Exposure 1 panels have a fully waterproof bond and are designed for applications where construction delays may be expected prior to providing protection. Exposure 1 panels are made with the same exterior adhesives used in Exterior panels. However, because other compositional factors may affect bond performance, only Exterior panels should be used for permanent exposure to the weather. Note: APA Rated Plywood Sheathing Exposure 1, commonly called “CDX” in the trade, is sometimes mistaken as an Exterior panel and erroneously used in applications for which it does not possess the required resistance to weather. “CDX” should only be used for applications as outlined under Exposure 1 above. For sheathing grade panels that will be exposed permanently to the weather, specify APA Rated Sheathing Exterior (C-C Exterior plywood under PS 1).
