OSB used for interior and exterior projects will accept stain and clear coat sealing products. Align the OSB so that it's straight and square. Only use products that are true OSB. To prepare the plywood, you will need to sand the surface to remove any dirt, debris, and loose particles. OSB substrate for waterproofing systems. The essential element for a proper and smooth finish is even coating. Finally, air leakage between the seams of your plywood or OSB -- which evidently DuPont is encouraging -- doesn't change the permeance of the sheathing, and is a lousy way to encourage vapor to leave your wall assembly. . Although it is a tough form of processed wood, but it will rot if it is left outside untreated. To prevent it from surface cracking, plywood demands sealing which not only saves it from water damage and decay but also ensures its long-term performance and endurance. For additional strength in OSB wood, purchase a grade that is marked "exposure" and "exterior." Hi – Thanks for the article. Tim Carter of Ask the Builder states, "There are products out there that look like OSB. It comes in a variety of finishes made to resemble various hardwoods and stucco surfaces. Martin's article says that it's best to use a primer and I fully agree. We are sure that you have got complete knowledge of sealing plywood and will be able to seal your wood like a pro! For best results, follow the mentioned timeline. OSB used for interior and exterior projects will accept stain and clear coat sealing products. For general sealing you might do better to create an air barrier, that might mean sealing around outlets and baseboards. NOTE, OSB (oriented Strand Board) is intended for exterior use. Hi Andrew. It will be prone to become rotted, soft, and break. The most common types of exterior plywood are CDX, marine-grade, pressure treated, OSB, and T-11. Mr. Handyandy Screwfix Select. Dakota Wright is a freelance journalist who enjoys sharing her knowledge with online readers. OSB is so strong in fact that it is now used for about 70% of all floor, wall and roof sheathing in North America and there are two different types of OSB, OSB2 and OSB3. Can I paint OSB for exterior use? Exterior paint will create a thin latex layer of protection over the surface. It normally comes in piles of 3, 5, 7, 9, and the lowest number indicates the uppermost class of a CDX plywood. Greater strength. Acceptable Types of Wood. Structural fiberboard is dimensionally stable. Install OSB at least 6 inches off the ground to prevent moisture issues from splashing rainwater. Paint the OSB with two coats of a premium exterior topcoat. You'd normally see it in structural flooring hidden underneath carpet etc. Post by ayjay » Mon Oct 15, 2012 12:22 pm. New homes will usually see a few rainfalls before a roof is on, and as noted above, OSB doesn't handle moisture well. Inspect the OSB often and repaint as needed to protect it from the weather. While working with horizontal installations, pressure-treated plywood is a good choice. Marine-grade exterior plywood has knot-free sheets and is mostly used for … © Copyright 2020 Hearst Communications, Inc. If you want to use OSB to sheathe the walls of your shed, you need to build those walls like the walls of a house: with a weather-resistant barrier like Tyvek over the OSB, and then cover that with siding of some sort. Allow the paint … dvdvdvdve, i say again. If you seal plywood flawlessly, it will enhance your wood resistance capacity. Use an exterior water-based paint for best results. OSB vs. Plywood. 1. It is not usually stained or painted, but that doesn't mean that it can't be done. Cover the surface with masking tape. Air sealing the OSB sheathing, will Latex Primer work? Plywood is cut into almost any shape and absorbs paint quickly, making it … However, the sealing project can be sometimes tricky when it comes to sealing rough surfaces. I've sheathed my house with OSB, and intend to use Typar house wrap. TIA. When the filler hardens, it’s suitable for rasping, sanding, or drilling. Cover the entire surface of the plywood with a coat of any exterior water-based stain. Astramax, Apr 5, 2017 #6. Waferboards, flakeboards and such are not OSB. It’s like the turkey loaf of building materials. Or if you are “perfect” with your rainwater control such as when you use a fully adhered membrane – think roof membrane standing up applied to a wall. These offer varying degrees of water resistance, but waterproofing plywood edges, and to a lesser extent the board faces themselves, will significantly extend the life of plywood in any environment where water is present. 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