What is the primary difference between interior and exterior plywood?

The primary difference between interior and exterior plywood lies in the adhesive used to bond the layers of veneer. Exterior plywood is manufactured with waterproof or water-resistant adhesives, which allows it to withstand exposure to moisture, making it suitable for outdoor applications. Interior plywood, on the other hand, is typically bonded with adhesives that are not designed to resist moisture, meaning it should not be used in environments where it will be subject to significant dampness or water exposure.

This difference in adhesive composition is crucial for the performance and durability of the plywood in different environments. While thickness, grain pattern, and wood type can influence the characteristics and uses of plywood, they do not define the fundamental distinction between interior and exterior options as the adhesive does. Adhering to the correct plywood type based on the adhesive properties ensures the longevity and structural integrity of the application it’s used for.