What is OSB. OSB, on the other hand, stands for Oriented Strand Board which is a cheaper version of CDX. In many instances, it is rated for load bearing applications (depending on the OSB grade). To address these water issues, OSB and plywood manufacturers are refining their products. The same can't be said for OSB panels. OSB is, however also available in a version for exterior wall applications with a protective layer laminated to one side. We will be painting the board and are wondering which side should face outward that we can paint? This high-performance sub-floor is designed to help you avoid costly and time-consuming joint sanding. Water Resistance. No paint will do this. Then the APA determined that the repellant they applied (the slick side) wasn't near as water-resistant as they thought. It takes longer for water to soak osb and conversely, once water gets into osb it is very slow to leave. I am using 7/16th OSB on the inside of our shop/garage. OSB will swell, warp, and degrade unless it's kept safe from sunlight and perfectly dry. I say hogwash. Failures may occur as loss of connections to the structure if the OSB is softened around nails or construction screws. It has some inherent moisture resistance, due to the resins which hold together the strands, along with some wax which is added to the product specifically for this purpose. Thank you Adrian, Fort Lauderdale, FL. There are several grades of OSB and they are suitable for different things. If osb is made from aspen or poplar, it gets a big fat zero with regard to natural decay resistance. im replacing my subfloor in a mobile home in 3 of the rooms right now does it matter which side (smooth or roof) i should face up. Took a few years but it did. 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. which side of osb faces up. If handled properly, OSB can accommodate exposure to some water without swelling. Combining two layers of the impact resistant and high strength OSB with a thick insulating layer of Expanded Polystyrene (EPS), the resultant SIPs are strong, quick to erect and well suited to the residential construction industry. A question I often get asked when speaking with consumers is: “Do I use the wax side or the other side of OSB?” I always answer the question with this explanation: Depending on the type of resin being used, some OSB producers do use wax but the wax has nothing to do with the appearance of the board. The usual fix is to attack your subfloor with a belt sander after the roof is on, and to replace the worst of the OSB panels with new ones. Required nail spacing varies from 3 inches to 6 inches apart, depending upon type of nail and rafter spacing. This type of construction makes OSB is an incredibly strong material. Could you advise me please? Appearance: OSB is not attractive enough to serve as a floor covering.Not only is the chip-board appearance unattractive, but the surface is also often marked with grid lines and manufacturer markings. OSB is water resistant, but its sides and edges do tend to absorb water if they come in contact with it long term, so the bottoms and edges of the sheathing installation can wick up water, causing it to swell and warp. Re: How to make painted OSB look halfway decent? It carries an Exposure 1 classification, which means it can withstand normal exposure to … Many builders have turned to Huber’s Zip System sheathing, a type of OSB with a coating of resin-impregnated kraft paper. Neither this or ordinary plies are likely to survive all that long if any part is exposed to moisture. Manufacturing. Discussion in 'Remodel Forum & Blog' started by handy_wo_man, Jun 6, 2011. handy_wo_man New Member. Water eventually got in via edges. Failures may occur as point loads or fractures if water damaged OSB is, for example, in use as roof sheathing in an area subject to snow loads. I’ve always done it the rough side and nail lines out. Every single fiber or piece of wood in an OSB is saturated with a cocktail of resins designed to provide superior strength and waterproofing to the finished product. There has to be a reason. An engineered wood product, fire-rated OSB sheathing such as LP FlameBlock sheathing eliminates a layer of gypsum by combining an ignition-resistant, cementitious coating with a layer of OSB. Vinyl siding is cheap and DIY-friendly. Plywood vs. OSB: Which is Better? Alibaba.com offers 1,777 osb board water resistance products. Plywood that is rated for exterior exposure will resist damage from water, even if it gets saturated. OSB2 is for use in dry conditions for structural work; OSB3 can take more humid or damp conditions when used for load bearing; So if there is any doubt of the conditions your OSB is to be used in, go for the water-resistant type to be on the safe side. Answer. OSB has more going for it than just cost. Oriented Strand Board Cost; OSB costs roughly $6 a sheet of 4 x 8 sheathing. The letters C and D represent the grades of either side of the plywood, while X stands for exposure. The layer beneath the siding—the water-resistive barrier, or WRB—is what will protect the plywood or oriented strand board (OSB) sheathing from any water that sneaks in. Thank you for the email and question Kevin. OSB panels are created under enormous pressure as the wood strands and resins are compacted. Joined: Jan 17, 2011 Occupation: wife, mother and homemaker Location: West Virginia. Plywood is available in different grades such as MR grade (moisture resistant) for interior use, and BWR grade (boiling water resistant) for exterior use. I have no idea why I did it other than thinking try it I made some garage doors out of osb. I have read lots of articles online and the majority say to put dark side out and paint it. Resource-efficient builders appreciate that it can be made from small, fast growing trees, many of which come from tree farms rather than forests. Most panels are also treated with a sealant on the panel edges to retard moisture penetration. Friction occurs when objects move through water or air. Lesson learned. wall sheathing (OSB) with the smooth side out (the grade stamp side out). Watch this amazing video comparison of AdvanTech flooring vs OSB when placed in a water vacuum chamber. Plywood long ago lost its market leadership to oriented strand board (OSB), which is now the most-used sheathing and subflooring material. If OSB is used on the exterior side of the walls, then a water-resistive barrier must be applied. Foil-backed OSB is applied mostly in attics; however, it is also used in wall systems. OSB used for interior and exterior projects will accept stain and clear coat sealing products. Estimates put its market share as high as 75%, with much of that dominance thanks to cost-conscious production builders. OSB is not water resistant and hence cannot be used for exterior projects. OSB's Pluses. While Oriented Strand Board is water resistant, it is not waterproof and is less able to breathe and release moisture than plywood. OSB used to be allowed to be used as a water-resistant barrier (2003 IRC and earlier). Your OSB panels absorb water from the edges, and the paint won't slow that down. Moisture: OSB, when exposed to the weather, will eventually swell and bubble up.Minor instances of bubbling can be sanded, but for the most part, the OSB is irreparable and should be replaced. ive been putting the rough side … It can also be bought in 9 foot sheets, which means you can sheathe a wall from the top plate to the bottom of the floor joists with single, vertical sheets, leaving no horizontal seams. OSB (oriented strand board) is similar to plywood and used primarily for subfloors, covering exterior wall studs and roofing. This can be avoided with sealants, but it is an extra step that needs to be considered. It is made of wood chips, resin and glue, cast and baked together to produce a CDX-like sheet. A fella I work with installs his ext. A wide variety of osb board water resistance options are available to you, Oriented strand board (OSB) is a type of engineered wood similar to particle board, formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations. OSB can be made from small diameter trees such as Poplar that can be farmed but plywood requires larger diameter trees from old-growth forests. Plus, DryGuard comes with a 200-day no-sand warranty. A wide variety of water resistant osb board options are available to you, such as design style, usage, and warranty. The longer that water remains within osb the more likely it is to rot. Manufacturers of OSB often cover it with a water-resistant film and add borate compounds to the wood, making it toxic to insects like termites and wood-boring beetles. Exterior plywood (or appearance-grade plywood) is made with water-resistant glue, and its outer veneers are made from water-resistant wood making it ideal for siding or panelling. It is not usually stained or painted, but that doesn't mean that it can't be done. Also, they are very water resistant. I could see a big problem if water poured into OSB, but if it's air and vapor sealed on both sides, where is the problem? Air resistance is a type of friction between air and another material. Wood species has a significant impact. Yes, I am reluctant to drywall, because it's not an intended finish of our house and I can see where this money can be spent better elsewhere. OSB, or oriented strand board, is an engineered wood product often used as sheathing in walls, floors, and roofs.It is cheaper than plywood and, with no internal gaps, more rigid. Interior plywood is perfect for concrete forms, sheathing and subfloors. woodchucker: 4/11/14 7:39 PM: So for flooring the companies that make the mortar, or glues do not recommend OSB under any tile, or stone. Plywood can and does swell, but typically once it dries, it returns to its original size and shape. DryGuard® enhanced OSB Sturd-I-Floor® is a multi-layered, moisture resistant sub-floor with built-in protection from thickness and edge swell. Ring shank or specialized hurricane nails that have greater resistance to pullout are highly recommended. But I would probably agree that the product has changed, but that doesn't help my problem of it being CRAP. His theory is that the smooth side has a wax coating that sheds water more effectively. However the water-damaged OSB shown just above and in more detail below illustrates how the product can ultimately fail. It was invented by Armin Elmendorf in California in 1963. The panels are termite resistant and outperform timber stud and metal framed construction in both acoustic and thermal ratings. On the other hand, OSB releases more formaldehyde (which is a carcinogen that is off-gased) than plywood. It soaked up rather a lot of paint. Major differences between OSB and CDX Resistance to water. Environmental factors. Oriented strand board (OSB), with a thin layer of low emitting aluminum foil attached to one side, is a common type of thermal-radiant-barrier sheathing. OSB is strong and water-resistant. Alibaba.com offers 1,786 water resistant osb board products. You'll probably end up with OSB that has swollen edges, creating ridges like picture frames. 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