Is OSB Board are waterproof? 03 Sep 2021
OSB is water-resistant but not necessarily waterproof. The heat-curable resin adhesive that coats and bonds the strands to form the panel is waterproof. Unfortunately, saw cuts and sanding can damage safety and expose unprotected wood to moisture damage. The exposed grain acts like a sponge and draws in moisture which causes strands to swell.
OSB can be painted with a quality exterior oil-based or latex paint to further improve moisture resistance. It can be stained by using a water-resistant or waterproof product. Before choosing any paint to provide the desired finish to your project, make sure it is waterproofing or water-resistant for added protection. OSB Board UK