Plywood For The Roof: What Should You Choose
Posted on Last updated: May 1, 2020
The roof is perhaps the most important part of your entire home. The roof of your house covers and protects everything inside of those walls from the rain, snow, and sleet that come your way. You want to make sure that you are building a quality roof that will last you for decades to come, but you need the right kind of plywood for the roof. If it comes down to OSB or plywood for the roof, which one should you choose?
Understanding the different types of plywood for the roof, the thicknesses, and the common sizes can help you to make wiser decisions for your home. If you need a crash course in selecting the right plywood, this guide should make things a little easier.
How Much Should I Pay For Roof Sheathing Material In Clinton Township Mi
Roof sheathing material and attic plywood is a hidden underscore but a cornerstone of your roof structure. It’s never seen from the curb, and we rarely visit them unless we see leaks forming on our roof. However, because they’re professionals, experienced and reliable Clinton Township MI roofers definitely know the right amount to replace roof sheathing material accurately.
On the other hand, some unscrupulous contractors can charge you quite highly without your knowledge. Some of them will claim the replacement is paramount because your wooden roof structures have started to crumble and weaken. In turn, the “rush job” will require them to prioritize your roof and raise the price. Is this proper practice? CAA Quebec has a great case study about this — with the right resolution.
Finding The Right Roof Sheathing Material
As was the case on this roof, dry rotted 3/8 plywood would not hold the nails even if they were long enough you could pull them out by hand that is how weak it was. This means that you MUST replace old roofing plywood. Here is approximately how much different options cost:
5/8 inch $26.87 per sheet. This is the BEST product to use, because its very sturdy and high quality. If there is water damage it will preform significantly better than the 1/2 plywood. Note, that when you buy in bulk, the price drops to $24.18 per sheet. Bulk pricing is for at least 58 sheets or 18.5 squares. If your roof is smaller than this, you can still request the pro to buy 58 sheets, and use what is left over for other home improvement projects.
1/2 inch 24.85 per sheet. This is what most people use, and its ok quality. However, think about it this way: the difference in price between this and 5/8 is $2 per sheet or $6 per roof square. If the total job is 20 squares, the total material price difference is only $120 dollars, and you will be getting a significantly better quality material. Bulk pricing for 1/2 inch is $22.37 per sheet, and you need to buy 70 sheets.
OSB roof sheathing about 60% cheaper than standard plywood.. While its allowed by code, we strongly advise against using OSB for sheathing. The minute any moisture gets in, its starts to break apart within 2-3 months. Then, you will need to do expensive repairs, and will actually waste hundreds of dollars in the end.
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Diy Or Hire A Professional
Speaking of DIYers, should you do the sheathing yourself or should you hire a professional? It might be tempting to do it yourself especially if youre looking to save money. To know the answer to this question, answer these simple yes or no questions:
- Do you want the best results?
- Do you want to stay away from potential accidents?
- Do you want to save money in the long run?
If you answered yes to these questions, then you need to hire a professional. It doesnt matter how experienced of a DIYer you are. A professional will always do a better job provided that you hire the best one for the project. After all if youre better than them, you should be getting paid for it, right? Besides if youre not satisfied with their job, a professional will make it right to ensure the best results.
More importantly, hiring a professional will keep you away from potential accidents. Working on the roof is dangerous. You can easily slip and/or fall. You can create more damages. Simply put, its not safe.
In addition, hiring a professional can help you save money in the long run. Since they can ensure the best results, you will get your moneys worth. The job will also be done right which will minimize mistakes and wastage.
Whats The Minimum Thickness Of Plywood For Roofing
The minimum thickness of plywood for most roofs is 3/8 inches. Its the common choice for roofs with rafters set 16-inches apart with minimal roof load. However, roof pitch will affect the load a flat roof will have a heavy load on any section, while a steep roof will have a lighter load per square foot.
There are a few things to consider when choosing the minimum thickness of plywood for your roof sheathing.
The first is the span of the rafters or trusses. The longer the span, the thicker the plywood must provide adequate support. The second is the load that will be placed on the roof. If you expect heavy snowfall or high winds, you need to use thicker plywood.
Finally, you need to consider the climate in which you live. If you experience extreme hot or cold temperatures, you will need to use thicker plywood to prevent the sheathing from warping or cracking.
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Where To Put Vapour Barriers :
Materials that act as vapour barriers , including certain types of insulation, must be located within the assembly so that moisture moving from the inside to the outside does not condense and accumulate within the assembly. This means that vapour barriers should be located on the warm side of insulating materials. Canada Mortgage and Housing Corporation
Manufacturers spec sheets weve read claim perm ratings of between 1 and 2 perms, but that doesnt inspire a great amount of confidence given that that conclusion was obviously arrived at by using the most favourable of the available numbers. At least some of these panels are said to be perforated to allow for increased moisture permeability, but a close look at the panel in the photo above at least, shows no visible perforations. So if they are there, they are no bigger than a needle point.
It would seem then possible at least, for moisture to migrate through the EPS and condense on the sheathing, certainly if you believe the lower of the OSB perm ratings. Without seeing the long term results of insulated sheathing products or at least some independent research on it, Its hard to know what will happen.
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What Size Plywood For Roofing
The most common rafter spacing is 24 inches. You can get plywood sheets with a length of up to 4 x 10 feet and OSB comes up to 16 feet long in length.
Do Most people ask how many sheets of plywood do I need for my roof?
Most people want to know how much square-fit plywood is needed in the roofing. Obviously, you dont want to buy extra plywood. Which is of no use to you and a waste of money.
Standard plywood comes in 4×8 feet size. So how many square feet are there in 4×8 feet of plywood? To calculate it, you multiply the length by the width. So 4×8 feet plywood has 32 square feet.
To calculate how many plywoods are required for your roof. Calculate your roof as if you calculated plywood square feet .
For example, suppose some area of your roof is 1000 square feet. So divide by 32 into 1000. The number youll get is the number of plywood that you need. In case you need 32 plywood. Always buy one or two extra pieces of plywood for mistakes and wastage.
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How Many Overhangs Should A Plywood Roof Have
If youre building or remodeling a house, you have many questions to ask the architect and builder, such as what type of roof should I have?
How Many Overhangs Should A Plywood Roof Have? Not only are these details essential to the structural integrity of your home, but local and international building codes may also dictate them.
So, knowing this information beforehand can save time and money and keep your project running smoothly. This article will explain how much overhang a plywood roof should have.
The plywood roof decking overhang isnt a one-size-fits-all building question. The local building codes determine trim length low-snow areas require less overhang to cover the ice. The average eave trim should be 2-3 feet. In low-snow regions, you may require less than 3 feet of overhang, while in snowy areas, youll need more than 3 feet.
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Why Is Plywood Used In Roofing
In roofing, plywood is often selected due to its strength. Although the roof structure takes the majority of the weight, plywood needs to be able to support the rest of the roofing system. It is formed from multiple layers of wood bonded together with glue, and the grains run in alternate directions through each layer, which ensures the boards strength is evenly spread, makes the board resistant to shrinking or expansion, and also reduces the likelihood of any splitting when nailed.
Plywood is often used in roofing because it performs well when exposed to moisture over long periods of time. When plywood gets wet, it swells evenly across the plywood sheet, and then when it dries out it goes back to the normal sizing. The drying out period is relatively short, which means that it doesnt affect the roofing. In comparison, OSB board tends to swell along the edges and takes a lot longer to dry out, which can leave visible ridges along the edges of the boards .
How Much Should I Expect To Spend To Replace Roof Decking
Your roofer should charge you only for the labor and materials used for a roofing project. A standard piece of plywood roofing sheathing measures 4 x 8 feet, and anywhere from ¼ of an inch to -inch thick. The thicker the plywood your roofer uses, the more expensive the job will be. Your price could vary depending on how much the roofing company charges for labor, but generally, you can expect to spend between $70 to $100 for each sheet of plywood.
A 4 x 8 sheet of plywood covers about 32 square feet of roof areaand the average roof measures about 3,000 square feet. That means new decking could potentially add several thousand dollars to your roofing project.
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Whats The Most Common Thickness Of Plywood For Roofing
On roofs where rafters are spaced at least 20 inches apart, the recommended thickness of plywood is 1/2 or 5/8 an inch.
That said, 24 inches is the most common rafter spacing, and for that, plywood of 5/8 an inch thick is most suitable. Such thickness is enough to will most roof loads, which is why its the standard choice.
On roofs with particularly heavy loads, you may need to use plywood of 3/4 an inch thickness. No matter the thickness you opt for, make sure the plywood is suitable for exterior use, rated Exposure 1 or Exterior.
How Much Does Roof Sheathing Cost
During roofing, roof sheathing is priced cumulatively with the rest of the roofing work. You cannot have one contractor lay down the skeleton and another layout the roofing material.
But before the labor charge agreement, the roofing contractors will know which roof sheathing material to use.
Wood, Concrete, and Steel are priced differently. But different wooden materials could be priced the same as they are made from the same material, have the exact measurements, and even the same thickness.
The difference between the OSB and plywood costs around $50-$60, where OSB could cost $600 and plywood $660. It is the cost of installing 500 square feet of roof.
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Types Of Roof Decking
For residential structures, most roof decking is made fromplywood or a plywood composite called Oriented Strand Board, or OSB. OSB consists of intertwining wood strands that are bonded together with a waterproof resin. It is a popular choice as roof decking due to its low price point. Plywood, on the other hand, may be slightly more expensive than OSB but it is denser and offers greater protection against moisture.
However, these arent the only types of roof sheathing used in the industry. There are many types of materials that can be used for roof decking, some of which are suitable for particular types of residential roofing systems:
How Much Does Mdo Weigh
MDO: Medium Density Overlay is a type of exterior plywood specifically designed to be painted easily. Due to its extremely smooth surface, it holds paint better, and looks better after being painted, than other types of engineered wood panels.
The wood plies in MDO panels are typically softwood, and a thick, smooth layer of a highly water-resistant resin is applied to one or both sides of the panel.
A typical 4 x 8 sheet of 1/2-inch MDO weighs around 48 lbs.
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Questionable Practices At The Estimate Stage
These kinds of add-ons, after the repair job has begun, are unfortunately commonplace. To be sure of getting the job, some contractors employ the devious practice of submitting an incomplete estimateand therefore quoting a lower price than their competitors. The customer is then hit with a string of extras.
How much should you actually pay to service or completely replace roof sheathing material? Plywood isn’t too expensive. Usually, the prices depend on the manufacturer’s factory rates. Most distributors add their transport and distribution figures that raise the cost effectively.
Some other issues can raise the price of roof sheathing material repair or replacement. Rotten decking will require additional labor to completely tear off the roof material and plywood and replace it with fresh plywood. Inadequate decking is the plywood thickness isn’t enough and may not be enough to carry the asphalt shingle or dense metal material such as standing seam metal’s weight. Modernize has a great estimate on figures you’ll need to spend on replacing roof decking.
Problem : Storm Damage
While youll probably notice if a branch or other debris piles onto your roof, hail damage can be much more insidious. With 4,610 hail events in the U.S. in 2018, the states most susceptible are Texas, Kansas, Colorado, Nebraska and South Dakota. Shingles and panels are almost always replaced entirely rather than patched up, making the cost of hail damaged roof replacement higher.
Depending on the area in which you live, materials used and contractor, you can expect to pay between $400 and $800 per every 100 square feet for roof repair and replacement. If you end up needing a full roof replacement, it could cost you between $7,500 and $15,000 for the average home size and roofing style. You can check for a more exact estimate using an online roofing calculator.
Your roof shingles are probably rated to protect your roof from the worst hail damagebut small hailstones can still cause problems. Tiny holes in your roof can expose your underlayment to rain and other moisture, which will cause mold, rot, and leaks. An inspector can spot hail damage right away, so you can get your insurance on the case to repair or replace your roof. A claim thats filed too long after the initial weather event may not be covered by insurance.
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Different Material Options & types Of Roof Plywood
Yes, there are several different material options and types of roof plywood. An experienced roofer can help you pick out the right one, but its good for you to know what these options are.
Before we start talking about the different options, its important to note that plywood has different grades:
This is the highest grade there is. You wont see imperfections. Understandably, its the most expensive. Thankfully, its not really a requirement to use this grade for all roof applications.
Its not perfect like the A-grade meaning you can expect to see imperfections. However, its good enough to be used underneath roofing felt and shingles.
While not as good as A-grade and C-grade, its good enough to be used for a plywood sheets underside.
Here are your options:
This option is basically a specialized plywood grade. Its front has a C-grade while its back has a D-grade. X signifies the glue that bonds the veneers.
This is a popular option because it presents homeowners with functional but affordable roof sheathing. A half inch CDX plywood is often used with rafter with 24-inch spacing. If your roof carries a heavier load, like if theres less pitch and/or it snows in your area, a roofer may recommend the use of the ¾ inch variety.
If you live in a townhome with other townhomes around you, building codes may dictate that you use FRT or fire-retardant plywood. It works by a process called acid hydrolysis thats activated when its exposed to fire.
