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Roof decking (or roof sheathing) is the wooden boards that make up the foundation of your entire roof system. I like to say foundation because it’s what your shingles and the rest of your roofing components are installed on. Roof decking is one of the most important pieces of your roof system.
What is the purpose of roof sheathing?
Roof sheathing helps with the distribution of weight evenly across the entire roof. Because the sheathing boards are attached to the roof’s joints and trusses, which are the strongest support beams, they help make sure that heavy loads of precipitation and snow don’t cause sagging or bowing.
How do I know if my roof sheathing is bad?
If the roofline is in any way wavy, then it means your sheathing is damaged and needs to be replaced. You can also check for sagging from the inside. Go into your attic with a flashlight, and look up. If any areas of the roof appear closer to you than others, your roof is sagging, and it is time to call a professional.
Is sheathing the same as plywood?
Plywood sheathing (OSB or plywood) is often mistaken for plywood underlayment. They are not the same. Plywood sheathing is most often used to construct the structural sub-floor. OSB is constructed using long strips (strands) of wood that are held together with wax and adhesive.
What does roof sheathing look like?
Most roof decking, also called sheathing, is plywood or oriented strand board (OSB). These thin sheets of wood absorb moisture when exposed to it through excess condensation or a roof leak. From the outside, this looks like you have a bulging or bowing spot on your roof.
Is roof sheathing necessary?
Roof sheathing is important as it is a layer of wood and as mentioned above, it attaches to the trusses and joists on the roof. Then the shingles attach to the planks of wood. This keeps the water out of the home so it is a necessary part of the home.
What should I use for roof sheathing?
Typical types of wood used for roof sheathing are oriented strand board, known as OSB, and plywood, the most popular being OSB. 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. With edge support and the same snow load, 3/8-inch OSB can be used.
How long does roof sheathing last?
You can expect the wood roof sheathing of a home to last 100+ years. Although it should last for the life of the home, roof sheathing lifespan can be shortened by moisture penetrating it from both above and below.
What are some common problems with roof sheathing?
Wood sheathing will eventually rot as excess moisture continually collects on it and the material is unable to properly dry out. Some signs that roof sheathing is damaged or rotted include a sagging ceiling, noticeable roof leaks and missing patches of roof shingles or tiles.
Can you put new roof sheathing over old?
Although I don’t think installing new plywood roof sheathing over the old would be a grave mistake, I would not recommend doing it, for several reasons. The new plywood will have to be nailed to the rafters or roof trusses. The result could be a poorly attached roof surface, more vulnerable to wind damage.
Can plywood roof sheathing wet?
A: It is never a good idea to install a roof over wet plywood or any type of roof sheathing. Trapped water will boil when the sun heats the roof and the shingles will then have small pits where the steam finally escapes.
Is sheathing plywood exterior grade?
CDX is the most common exterior plywood grade. Oriented strand board (OSB) is an engineered plywood substitute that many builders use for sheathing and roof decking. It’s constructed with waterproof glue and performs best when only semi-exposed to the elements, as it is when covered with siding or roofing.
What is the minimum thickness of roof sheathing?
Sheathing must be a minimum of 19/32-inch thick. Never affix roof sheathing with staples; 8d ring-shank nails need to be used instead. The normal thickness range for sheathing is 3/8 to 3/4 inch.
Is roof sheathing structural?
Roof sheathing is structural, providing lateral bracing of roof framing members, and it carries both live and dead loads from above to the rafters and trusses below. Similar to exterior wall wood sheathing, roof sheathing includes plywood, oriented strand board and waferboard.
Is sheathing part of the roof?
Your roof sheathing is an important component of your roofing system. Sheathing holds up your shingles, keeps the elements out, and helps distribute weight evenly across your roof.
What is the difference between sheeting and sheathing?
As nouns the difference between sheathing and sheeting is that sheathing is something that wraps around or surrounds something, as a sheath encases its blade while sheeting is fabric used to make sheets (bedding).
Can you install metal roofing without sheathing?
Although it may seem counterintuitive, metal roofing can be attached directly to your building’s roofing structure without the need and expense of plywood sheeting.
How much does it cost to repair roof sheathing?
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.
Do I need plywood on my roof?
Aside from shingles and underlayment, plywood decking is one of the most important components in your roof. The plywood decking is integral in keeping your home free of unwanted water and mold. If the plywood has gotten wet, it can have a disastrous effect on the rest of your roof, especially the shingles.
