Plywood is a laminated material that accepts waterproofing easily. When plywood is used in any capacity outdoors, waterproofing prolongs its life. Since plywood is made by gluing layers of wood together and finishing it with a veneer, the layers are vulnerable to water damage. When plywood is exposed to excessive water, the glues disintegrate causing the wood to slowly rot and the layers to peel apart. Many waterproofing materials are easy to apply and dry quickly. Some do not change the appearance of the product.