Knowing this number can help you determine how many sheets of plywood you need for your roof. A flatter roof with rafters farther apart may need a thickness of up to ¾ inch. Hence, the cost to install it is lower. There’s a formula to be applied. This information makes it easier to coordinate with pros. Roofing plywood thickness? As always, add a few sheets to be sure. For a decking, or substrate underneath shingles, you can usually use either material. The minimum thickness of plywood used for roofing is 3/8 th of an inch. 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. Installing The Plywood Sheets. 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! This kind of plywood can be used on roofs with minimal load; steeper rather than flatter roofs will have lesser load per sq. You don’t want to buy too much because that will be an expensive waste. You can get plywood sheets with a length of up to 10 feet. Yes, there are several different material options and types of roof plywood. 1. (Source: International Association of Home Inspectors). Every piece meets the highest grading standards for strength and appearance. I saw no voids along any cut edges, so the grade was likely AB. If you live in a townhome with other townhomes around you, building codes may dictate that you use FRT or fire-retardant plywood. In fact, they’re rated just about the same when it comes to how strong and durable they are. Especially if the trusses or rafters are set on 24" centers. RVM103 NHSO On the road since June '12 with Lincoln, the … But the common plywood is 3.2mm~21mm . You might be tempted to choose a ¾ inch thickness although it’s unnecessary in most cases. Plywood used for roof decking is typically called sheathing and carries a grade stamp indicating its load and span ratings and other performance factors. 1/2″ is the minimum, but 3/4″ was standard in the part of the country I was in. The thickness of the sheet is determined by the ply. X signifies the glue that bonds the veneers. This is a popular option because it presents homeowners with functional but affordable roof sheathing. © Copyright 2020 Hearst Communications, Inc. 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. Every piece meets the highest grading standards for strength and appearance. Let’s say that your roof has a total of 1,500 square feet. In some parts of the country, they still use 1X boards for the decking. You’ll also learn how to calculate to find out how many sheets you need for your roof. We made this process easier. That’s considered to be the minimum. There two Plywood Thickness : Nominal Thickness and Actual Thickness. You need to shop around in order to get the best quotes to choose from. It might be tempting to do it yourself especially if you’re looking to save money. Unsanded, plywood sheathing panels are specially designed for walls and roof applications. This minimum will only work if the rafters are set 16 inches apart at most and if the roof doesn’t have too much load. The number you’ll get is the number of sheets that you need. OSB offers several benefits. More ply creates a thicker and stronger board. Since the boards used for shiplap were manufactured here in the Pacific Northwest, it was still cheaper than plywood up through the 1960s. Should you use CDX (plywood) or OSB (oriented strand board) for roofing plywood? Multiply that by 2 if you have a gable roof and that’s the total square footage of your roof. Plywood span ratings indicate the distance between framing members for roofing and flooring … followed by the plywood thickness. You’re in luck if you have a conventional gable roof because it should have slopes on each side that are identical in dimensions. My 25 year shingles have just about fried off (in 14 years) and every time I go up there to check things out the roofing plywood is so weak I think I am going to end up in the living room. This wood is just like regular framing lumber, except it has been factory … Divide that by 32 (the square footage of each 4×8 plywood sheet). A flatter roof with rafters farther apart may need a thickness of up to ¾ inch. About 1% of these are plywoods. You can use a caliper to measure the thickness as showing in above photo. An experienced roofer can help you pick out the right one, but it’s good for you to know what these options are. There are many different types of roofing materials that are available in markets such as Metal roofing, Stone-coated steel, Rubber slate, Solar tiles, Asphalt shingles, Green roofs, and more. Roofing Types Many different roofing products are now available for use and installation over a plywood substrate. Thankfully, it’s not really a requirement to use this grade for all roof applications. 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. 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. The most common rafter spacing is 24 inches, and 5/8-inch plywood is recommended for that. And there will be less wood for the roofing to fasten to, that is the most important. Depending on thickness, plywood is also approximately two pounds or more lighter per sheet. It has been estimated that OSB has a stronghold of ¾ of the market share, mainly because it’s the more affordable option. Obviously, it should be graded for exterior use meaning it should be able to withstand rain especially during the construction of the roof. Get Free, No-Obligation Quotes, It only takes 2 minutes to fill out the form. What thickness and grade of plywood should be used for my roof decking? With 24-inch truss/joist spacing, the National Wood Flooring Association recommends 1-inch OSB underlayment, compared to 7/8-inch plywood. 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. Let’s say that the main floor area is 10 by 20 feet and the wing floor area is 10 by 15. Nominal Thickness and Actual Thickness of Plywood. If your roof is more on the flatter side, then it’s expected to have a heavier load. Plywood's Advantage over OSB? For heavy load rated areas, 3/4-inch-thick plywood is recommended, regardless of rafter spacing. Builders like to use plywood, due to its structure stability, water resistance, and low cost. For example, if your roof is 1,500 ft 2 then it will take 47 sheets of plywood to sheath it. You are almost done - fill out this last step. Roof zone 27.5; 16 separate weather-related; Roofing hooks roofing vancouver; Keep in mind that the load of the roof still plays a role in the plywood thickness. 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. Generally 12 – 15mm ply is the most commonly used thickness. What is plywood? Sheathing should be a minimum of 19/32-inch thick. Oriented standard board (OSB) is created much differently. If it does, it can stay that way even if you dry it out. Roofing plywood thickness? foot and with a maximum of spacing of 16 inches between rafters. It should have a minimum thickness of 18mm. What Size Plywood should You Use for your Roof? While plywood remains a good and viable option, the fact remains that OSB is now the preferred choice. It works by a process called acid hydrolysis that’s activated when it’s exposed to fire. In this case, you need 29 sheets (rounded off from 28.13). OSB is also more affordable. 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. 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. Thicknesses of 1/2 to 5/8 inch are common with rafters spaced at 24” centers. The thickness required by Josh’s circumstances are good for roof snow loads of up to 70 psf (again spanning 24”). Simply put, it’s not safe. The minimum thickness of plywood used for roofing is 3/8 th of an inch. OSB is incredibly more cost-efficient than plywood. It’s the standard for spacing of 24 inches in the rafter, although as mentioned, a 5/8 inch thick is more ideal. So, what size plywood should you use for your roof? 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. A professional will always do a better job provided that you hire the best one for the project. Follow these steps when installing metal roofing on top of plywood: Inspect the existing roof. Exterior grade plywood and OSB are the two main choices for roofing. If they know that you’re shopping around for the best deal, you can expect to get the best quotes. 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). That, in a nutshell, is the one big advantage plywood holds over OSB. Most roofs are spaced at least 20 inches apart. After the 1960s, the predominant residential roofing substrate became 1/2″ CDX plywood. The typical thickness of roof sheathing is about 7/16-inch, which is just under 1/2-inch. The ideal thickness for the standard rafter spacing of 24 inches is 5/8 th of an inch. Keep in mind that the load of the roof still plays a role in the plywood thickness. Contents. 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. Need help with your next OSB project? That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. This removes flexibility in the floor and helps reduce deflection. That’s considered to be the minimum. For this, you can either go for a half inch or 5/8 inch thick sheet. The Minimum Plywood for Roofing Plywood Is Layers of Wood. It has its own strengths. ... Sheathing Thickness. The typical thickness range for sheathing is 3/8 to 3/4 inch. Plywood is sold in various ratings, grades and sizes. The choice of Plywood should be exterior grade per British Standard (BS) 5268-2, WBP (Water & Boil Proof) to BS EN 636-2:1997. R905.2.8.2Valleys. This thickness will ensure that the wood is sturdy enough to hold the screws in place and support the metal roofing. 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. Need help with your next OSB project? While it’s not the main material for the roof itself, roofing plywood is an important part in a roofing structure. The waterproofed coat of plywood makes it a top choice along with OSB, planks and wood boards. The plywood or OSB you use for a base underneath your metal roofing should be at least 7/16 inch thick. This option is basically a specialized plywood grade. Plywood Roof Sheathing Panels Gp PlytaniumCdx Plywood TheplywoodSheathing Plywood The Home DepotBuilding Construction FinishingWhat Type Of Plywood To Use For A ShedThe Right Plywood … The main floor area is 600 square feet and the wing floor area is 150 square feet. With edge … x 4 ft. x 8 ft. Rtd Southern Yellow Pine Plywood Sheathing Plywood sheathing is ideal for residential Plywood sheathing is ideal for residential and light construction. "World." Rafters run from the peak of the roof to the eaves. The only downfall when comparing the two materials is cost. Divide that by 32 to get the number of sheets needed. Roofing Plywood Thickness. I don't think 3/8 is ever enough. The roofer originally spec'ed OSB (not sure of the thickness but 7/16" is typical) but I didn't feel good about that so I spent a little bit more and got plywood. You'll find varying opinions (some quite strong) on the OSB vs. plywood debate for sheathing. For rafters spaced 20 or more inches apart, 1/2- or 5/8-inch plywood is recommended. We set aside a whole section in this article for you to compare the two and determine which one is better. How Many Square Feet in a 4×8 Sheet of Plywood – How Many Sheets of Plywood Do I Need for My Roof. Differences Between OSB and CDX For Roofing Plywood. I saw no voids along any cut edges, so the grade was likely AB. The roofer simply puts the panels in place and then seals the seams using tape. A 4×8 sheet of plywood is 32 ft 2. The recommended shed floor plywood thickness is 3/4 inch pressure-treated exterior-grade CDX plywood. The thickness needed will depend on the purpose and use-case. What we don’t recommend is for you to hire the first contractor with a good offer. Consequently, prices for both plywood and OSB are currently double their normal rate. Different Material Options & Types of Roof Plywood. Is there a better choice between the two or will either one work just fine? Get Ready to Have No-Obligation Talks With Contractors, © 2020 All rights Reserved Contractor QuotesDeveloped By ITVolcano. This makes it more energy efficient. It doesn’t swell when it gets wet unlike OSB. The minimum number of plies are 3-ply and can go up to 5 or more. Originally, plywood was the go-to choice for roof decking. In high winds, the less roof sheathing thickness, the more likely the roofing … 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. Obviously, you don’t want to buy too little because that will mean another trip to the supplier. The roof deck will be too soft. It doesn’t matter how experienced of a DIYer you are. Available either untreated or H3.2 CCA. Bring out the calculator. It is certainly not preferred by professionals interested in quality. In this case, a 4×8 sheet of plywood is 32 square feet. A wide variety of plywood thickness for roofing options are available to you, such as e2, e0, and e1.