Waterproof plywood is suitable for use in exterior conditions or for the manufacture of products that will be used in contact with moisture. The adhesive used in this type of plywood (phenol-formaldehyde resin) is waterproof. The waterproof glue ensures that the veneer layers do not separate when exposed to water. As the outer surface of the plywood itself is not waterproof, the board should be protected from moisture by coating it with paint, varnish or stain, which will ensure water resistance and protect it from external weather conditions.