Thickness looked to be 3/8" or metric equivalent. In this case, you can’t use a 3/8 inch thick sheet. How many square feet are there in a 4×8 sheet of plywood? How Many Square Feet in a 4×8 Sheet of Plywood – How Many Sheets of Plywood Do I Need for My Roof. Ecoply Roofing features a tongue and groove profile on the long edge That’s considered to be the minimum. A standard sheet of plywood is 4×8. The minimum thickness of plywood used for roofing is 3/8 th of an inch. If it does, it can stay that way even if you dry it out. We also carry pre-cut project panels that are available in different sizes that may vary by store. These manufacturers have shown that they feel more comfortable working with plywood. The typical thickness of roof sheathing is about 7/16-inch, which is just under 1/2-inch. Should you use CDX (plywood) or OSB (oriented strand board) for roofing plywood? Different Material Options & Types of Roof Plywood. About 1% of these are plywoods. This wood is just like regular framing lumber, except it has been factory … Ply means layer. Do you want to stay away from potential accidents? After all if you’re better than them, you should be getting paid for it, right? Plywood Ratings, Grades & Sizes. Also known as sheating, decking is basically where the roofer attaches the shingles or whatever your chosen roofing material is. Check out the Roofing Insights Directory! We’ll discuss plywood vs OSB more later. Metric Thickness and Imperial Thickness . I can 't remember the grade stamp, but I know the outside plys were clear. Generally, plywood comes in 4 by 8-foot sheets, and in a variety of grades. We will not contact you with anything else. OSB is also more affordable. A 4×8 sheet of plywood is 32 ft 2. Need help with your next OSB project? More ply creates a thicker and stronger board. Bob Haring has been a news writer and editor for more than 50 years, mostly with the Associated Press and then as executive editor of the Tulsa, Okla. Sheathing should be a minimum of 19/32-inch thick. Builders like to use plywood, due to its structure stability, water resistance, and low cost. The savings you’ll get per sheet will really add up. They will pay you $100 to try one of their roofers, in addition to the $20,000 guarantee that Roofing … You might be tempted to choose a ¾ inch thickness although it’s unnecessary in most cases. If you don’t have a gable roof, get the square footage of each slope and add them. Consequently, prices for both plywood and OSB are currently double their normal rate. Generally 12 – 15mm ply is the most commonly used thickness. Depending on thickness, plywood is also approximately two pounds or more lighter per sheet. One of the major differences between OSB and CDX plywood is how well each holds up against water. As always, add a few sheets to be sure. Before we start talking about the different options, it’s important to note that plywood has different grades: This is the highest grade there is. You won’t see imperfections. You don’t want to buy too much because that will be an expensive waste. Speaking of sheets, it’s available in 4×9 sheets. Today, a shiplap roof is usually 60+ years old. The roofer simply puts the panels in place and then seals the seams using tape. This material separates the roofing from the substrate, provides secondary weather protection and guides drainage down the side of the roof. Hence, the cost to install it is lower. Ply roof sheathing provides a safe substrate for roofing crews and can eliminate tile battens or purlins from the framing cost. Its front has a C-grade while its back has a D-grade. This is especially true among experienced DIYers who mastered DIY tasks working with plywood. Strong and durable, this engineered wood product has a barrier that resists water but still allows it to breathe. An experienced roofer can help you pick out the right one, but it’s good for you to know what these options are. The minimum thickness of plywood used for roofing is 3/8 th of an inch. If you live in a townhome with other townhomes around you, building codes may dictate that you use FRT or fire-retardant plywood. Roofing Types Many different roofing products are now available for use and installation over a plywood substrate. In addition, hiring a professional can help you save money in the long run. The most common plywood sizes are 4- x 8-feet sheets and 5- x 5-feet sheets. I saw no voids along any cut edges, so the grade was likely AB. While plywood remains a good and viable option, the fact remains that OSB is now the preferred choice. Plywood is sold in various ratings, grades and sizes. Use a staggered pattern when building up rows of plywood sheets. Roofing plywood thickness? That, in a nutshell, is the one big advantage plywood holds over OSB. I don't think 3/8 is ever enough. Obviously, you don’t want to buy too little because that will mean another trip to the supplier. Most roofs will be sheathed in plywood at least 3/8 inch thick. To secure it, measure it, roll it out over the plywood, cut it to the dimensions of the roof with a roofing or utility knife and finally hammer it securely to the plywood with 1/2-inch roofing nails. OSB offers several benefits. Plywood vs. OSB (oriented strand board) - Ironically, OSB takes longer to get saturated when wet, but it also takes substantially longer to dry. The choice of plywood grade depends on the type of roofing, and on the level of finish required. Plywood is used almost in exterior and interior construction applications. In some parts of the country, they still use 1X boards for the decking. Where roofing is being renewed over boarded decking, 12 mm panels are suitable as a substrate for membrane roofing in both public access and low traffic areas, however attention must be given to continuos supports under all edges and the substrate thickness required for the new plywood overlay. Occasionally I have seen 3/8" plywood on a roof. Understandably, it’s the most expensive. Roofs with very heavy loads may require 3/4-inch thickness. Installing metal roofing over plywood is less time-intensive and more affordable than a shingle roof, but there are still several steps you should take when installing a metal roof to plywood to ensure that your roof does not leak and will stand the test of time. Plywood with lesser number plies are thinner and weaker even if they’re of the same thickness. Sheets of 7/16-inch thick, with no edge support, can be used in an area where the snow load is 30 pounds per square foot. Divide that by 32 to get the number of sheets needed. You’ll also know about the different material options. To know how many sheets for the roof sheathing is required it`s enough to make simple calculations. This option is basically a specialized plywood grade. OSB is another popular choice. A wide variety of plywood thickness for roofing options are available to you, such as e2, e0, and e1. Install a felt moisture barrier. That’s considered to be the minimum. I prefer to see the use of asphalt felt underlayment, because asphalt felt allows OSB or plywood roof sheathing to … Ready to talk to screened pros? This thickness will ensure that the wood is sturdy enough to hold the screws in place and support the metal roofing. OSB is incredibly more cost-efficient than plywood. Roofs are framed with rafters or trusses, which are rafters joined by internal braces so they install as a single component. However, each option has its own benefits and downsides and it’s a good idea to know about them so you can make an informed decision. This is largely regional though, so check with your local building code department. The ideal thickness for the standard rafter spacing of 24 inches is 5/8 th of an inch. The industry offers a thickness of anywhere from 5/16 inch to ¾ inch. The main floor area is 600 square feet and the wing floor area is 150 square feet. I spent 4 years representing a roofing company in NC. The material is strong, durable, and tested over time. What if you have a complicated roof wherein you can’t measure this way? What Size Plywood for the Roof? To secure it, measure it, roll it out over the plywood, cut it to the dimensions of the roof with a roofing or utility knife and finally hammer it securely to the plywood with 1/2-inch roofing nails. As a warning, it’s considered by some to be inferior in quality as compared to plywood. We recommend hiring a professional contractor for this task. Depending on thickness, plywood is also approximately two pounds or more lighter per sheet. Roof sheathing comes in grid-marked 4-by-8-foot sheets, and should be installed perpendicular to the frame. The ideal thickness for the standard rafter spacing of 24 inches is 5/8 th of an inch. What thickness and grade of plywood should be used for my roof decking? Range. Let’s say that the main floor area is 10 by 20 feet and the wing floor area is 10 by 15. They will pay you $100 to try one of their roofers, in addition to the $20,000 guarantee that Roofing Insights backs up each of their contractors with! It’s the standard for spacing of 24 inches in the rafter, although as mentioned, a 5/8 inch thick is more ideal. _____ John & Diane, Fulltimers. Ecoply is manufactured under a third-party-audited quality control programme and is certified by the Engineered Wood Products Association of Australasia (EWPAA) as compliant with AS/NZS 2269 Plywood Structural. Alibaba.com offers 961 roofing plywood thickness products. The plywood is further divided into two grade that is MR grade and BWR grade. Roofing plywood allows to settle roof effectively and cost-effectively. For heavy load rated areas, 3/4-inch-thick plywood is recommended, regardless of rafter spacing. A professional will always do a better job provided that you hire the best one for the project. Contents. The thickness of plywood used for roof decking depends on the roof slope, the spacing of rafters and the weight of other material to be put over the decking, as well as the design "load" — the amount of pressure exerted by various forces and the weather, especially weight of snow or ice accumulations. You’re in luck if you have a conventional gable roof because it should have slopes on each side that are identical in dimensions. Thicknesses of 1/2 to 5/8 inch are common with rafters spaced at 24” centers. Look for something that’s graded as Exposure 1 or Exterior. Plywood's Advantage over OSB? Measuring the Plywood Thickness . There two Plywood Thickness : Nominal Thickness and Actual Thickness. Make your selection based on the type of project you’re working on. Ecoply Roofing features a tongue and groove profile on the long edge Talk to a professional so that the factors will be properly considered so you can make the right choice on the best wood. Obviously, it should be graded for exterior use meaning it should be able to withstand rain especially during the construction of the roof. Roofing Plywood Sizes Material Options Thickness Calculations Osb 8 tips for getting the best out of your oriented strand board osb oriented strand board osb vs plywood family handyman roof deck materials to ensure a le surface iko add or modify a steel joist and plywood osb roofing system roof deck materials to ensure a le surface iko what you need to know about roof sheathing. It’s so important that you have to arm yourself with knowledge and know everything there is to know so you’ll know the best way to utilize it for your roof. Thicker panels are more rigid and durable but are also heavier and more expensive. I'm not a fan of the use of peel-and-stick membrane to cover 100% of a roof. 1. It has its own strengths. Get the width and length of each slope of the roof. Although plywood is traditionally used to create the roof deck, it’s becoming more popular for contractors to use OSB. (Source: International Association of Home Inspectors). Common Plywood Thickness. For many applications, a layer of plywood underneath your metal roofing is an unnecessary expense. Base flashing shall be of either corrosion-resistant metal of minimum nominal 0.019-inch (0.5 mm) thickness or mineral-surfaced roll roofing weighing not less than 77 pounds per 100 square feet (4 kg/m 2). We made this process easier. The choice of Plywood should be exterior grade per British Standard (BS) 5268-2, WBP (Water & Boil Proof) to BS EN 636-2:1997. 1/2" CDX plywood is on my newly redone roof. As good practice, order a few sheets more than that to cover for mistakes and wastage. Until the 1940s, exterior grade plywood was not available. 1/2″ is the minimum, but 3/4″ was standard in the part of the country I was in. So, what size plywood should you use for your roof? Installing The Plywood Sheets. Do you want to save money in the long run? 11/32 in. Is there a better choice between the two or will either one work just fine? Follow these steps when installing metal roofing on top of plywood: Inspect the existing roof. Besides if you’re not satisfied with their job, a professional will make it right to ensure the best results. This plywood is strong and durable enough for use in roofing, framing and other exterior, structural projects. Metal roofing panels rated for "architectural use" attached to purlins (horizontal pieces of wood or metal fastened to roofing trusses) are structurally sound when installed according to your roofing manufacturer's instructions and local building codes. An instance of similar calculations is given below. Regardless of thickness, the plywood should be a type suitable for exterior use, graded "Exterior" or "Exposure 1.". With 24-inch truss/joist spacing, the National Wood Flooring Association recommends 1-inch OSB underlayment, compared to 7/8-inch plywood. Speaking of OSB, it’s a top choice of homeowners looking for something more affordable than plywood. The edges of OSB may noticeably swell when exposed to moisture. foot and with a maximum of spacing of 16 inches between rafters. You now have a total of 750 square feet. You’ll also know the different size and thickness requirements. You'll find varying opinions (some quite strong) on the OSB vs. plywood debate for sheathing. Range. It is rot resistant with knots replaced with football shaped plugs to give it a smooth moisture-resistant surface. In the photo, the caliper reads 17.75mm, which is the actual thickness, the nominal thickness of this plywood is 18mm plywood. 1,500 ÷ 32 = 46.875 sheets Measure the floor area of everything covered by the roof. But still, no one will blame you if you choose plywood over OSB. Just to get one thing straight, either one will work just fine. Get Free, No-Obligation Quotes, It only takes 2 minutes to fill out the form. The thickness required by Josh’s circumstances are good for roof snow loads of up to 70 psf (again spanning 24”). This kind of plywood can be used on roofs with minimal load; steeper rather than flatter roofs will have lesser load …. Should you use CDX (plywood) or OSB (oriented strand board) for roofing plywood? Loads will vary with the pitch of the roof; the flatter the roof, the greater the load on any one section. It can be used for the project once the roofing contractor confirms its suitability for the work. The roof deck will be too soft. Roofing Plywood Thickness. Open spaces form between the once tightly-fitted shiplap boards. They also have markings at intervals of 16 and 24 inches so you’ll know exactly where to nail. RVM103 NHSO On the road since June '12 with Lincoln, the … Knowing this number can help you determine how many sheets of plywood you need for your roof. The job will also be done right which will minimize mistakes and wastage. Nominal Thickness and Actual Thickness of Plywood. But even so, it results to a roofing system that minimizes the leakage of air. You can easily slip and/or fall. In this case, a 4×8 sheet of plywood is 32 square feet. Let’s say that your roof has a total of 1,500 square feet. This is because OSB is created by taking woodchips, gluing them together, and hot-pressing them down. It has been estimated that OSB has a stronghold of ¾ of the market share, mainly because it’s the more affordable option. But the common plywood is 3.2mm~21mm . Cap flashing shall be corrosion-resistant metal of minimum nominal 0.019-inch (0.5 mm) thickness. The number you’ll get is the number of sheets that you need. Do You Need Permits To Remodel a Bathroom? Since retiring he has written freelance stories and a weekly computer security column. What is the best shed floor plywood thickness? Multiply the width and length of each slope and you should get the square footage of that slope. The plywood must be exterior grade for all wet areas and it has to be installed in such a way that the joints between each layer do not line up, using what is known as a stagger pattern to keep the pieces from ever lining up. OSB comes in 4-by-8-foot sheets, as does plywood, but the manufacturing process allows the production of longer and wider ones. What plywood should you use for a roof? Exterior grade plywood and OSB are the two main choices for roofing. Check out the Roofing Insights Directory! Need help with your next OSB project? The Minimum Plywood for Roofing Plywood Is Layers of Wood. Working on the roof is dangerous. For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kN/m2. A half inch thickness is considered to be standard in a lot of areas and it should work just fine considering that it’s deemed okay by the roofing contractor after considering the things above. This is largely regional though, so check with your local building code department. Moisture Differences . Every piece meets the highest grading standards for strength and appearance. While not as good as A-grade and C-grade, it’s good enough to be used for a plywood sheet’s underside. While it’s not the main material for the roof itself, roofing plywood is an important part in a roofing structure. This is a popular option because it presents homeowners with functional but affordable roof sheathing. Roof decks on homes built before 1970 are often 1×8 fir pre-plywood shiplap. That, in a nutshell, is the one big advantage plywood holds over OSB. A 4×8 sheet of plywood is 32 ft 2. Even the Engineered Wood Association agrees to this. The wider the rafter spacing, the heavier the shingling, the lower the slope and the heavier the weather load, the thicker the plywood will have to be. The plywood or OSB you use for a base underneath your metal roofing should be at least 7/16 inch thick. I can 't remember the grade stamp, but I know the outside plys were clear. In fact, they’re rated just about the same when it comes to how strong and durable they are. Once the spacing hits 24 inches, a 5/8 inch thick sheet is more ideal. A wide variety of roofing plywood thickness options are available to you, such as type. After the 1960s, the predominant residential roofing substrate became 1/2″ CDX plywood. How to Put Rigid Foam Insulation on the Roof Before Putting on Shingles. The standard width is 4 feet. Multiply that by 2 if you have a gable roof and that’s the total square footage of your roof. About 0% of these are Steel Sheets. Plywood is made with three or more layers of thin wood glued together with the grain alternating. Never attach roof sheathing with staples; 8d ring-shank nails should be used instead. If your roof carries a heavier load, like if there’s less pitch and/or it snows in your area, a roofer may recommend the use of the ¾ inch variety. What we don’t recommend is for you to hire the first contractor with a good offer. It doesn’t swell when it gets wet unlike OSB. Plywood also has a slight advantage in stiffness, which means that subflooring panels do not need to be as thick. Plywood span ratings indicate the distance between framing members for roofing and flooring … followed by the plywood thickness. The recommended shed floor plywood thickness is 3/4 inch pressure-treated exterior-grade CDX plywood. Allow them become larger troubles as well as roofing substitute simply months from currently implies you invest 4, also 5 numbers. For the curious – 7/16” OSB has a span rating of 24/16 and with supports every 24 inches is good for a roof live load of 40 psf (pounds per square foot) with a 10 psf dead load. September 14, 2020 Editor. It is typically made in 4-by-8-foot sheets, although longer panels are available for special purposes. In this case, add 150 to get a total of 900 square feet. It should have a minimum thickness of 18mm. Typical types of wood used for roof sheathing are oriented strand board, known as OSB, and plywood, the most popular being OSB. They must be covered with some type of sheathing or decking before most finishing roof materials can be applied. Panel thickness will also affect permeability - using the 2 perm variable of 7/16ths OSB sheathing, at 3/4" thickness the permeability drops to 2/3rds of a perm. The correction recommended by manufacturers is installation of an additional layer of 3/8-inch minimum exterior-grade plywood or OSB roof sheathing on top of the original wood-board roof sheathing. You can create more damages. Steeper roofs will have lighter loads per square foot. Unlike with plywood siding, the plywood sheet to be used for sheathing should be at least 3/8 inch thick. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Roofing services rotted roof decking building code for roof sheathing building construction finishing roofing services rotted roof decking roofing services rotted roof decking types of plywood the home depot. Many homes have rafters that are even wider at 24 inches apart and will require a thicker sheet of plywood. The major factor to best plywood for rv roof repair is so you with any luck do not need to pay of changing a roof covering. The minimum thickness allowed for ceramic tile installations is two sheets of 5/8-inch thick plywood. Adding 20% is industry practice. It is a flexible, durable, inexpensive covering for roofs because each panel will cover 32 square feet. If they know that you’re shopping around for the best deal, you can expect to get the best quotes. You’ll know how it’s used for decking and sheating. If you take a look at a sheet of OSB, you’ll notice the surface isn’t extremely smooth. Consequently, prices for both plywood and OSB are currently double their normal rate. This removes flexibility in the floor and helps reduce deflection. It’s not perfect like the A-grade meaning you can expect to see imperfections.