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Most roofs will be sheathed in plywood at least 3/8 inch thick. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Loads will vary with the pitch of the roof; the flatter the roof, the greater the load on any one section.
How thick is typical roof sheathing?
Sheathing Thickness The typical thickness of roof sheathing is about 7/16-inch, which is just under 1/2-inch.
What type of plywood is used for roofing?
CDX is the grade of plywood most commonly used for roofing (CDX plywood means it is Construction Grade for exterior purposes).
Is 7/16 OSB OK for roofing?
Standard types of wood designed for roof sheathing are oriented strand board, known as OSB, and plywood, the most popular being OSB. Sheets of 7/16-inch thick, without edge support, can be used in an area where the snow load is 30 pounds per square foot.
Can I use 1/2 inch plywood for shed roof?
If the shed is for light tools then 1/2 inch pressure treated plywood is acceptable. If the shed is for heavier storage, then pressure treated 3/4 inch exterior-grade CDX plywood is the best.
What is the best sheathing for a roof?
OSB is now the most-used sheathing and subflooring material for new roofs and roof replacements.
Should you use tongue and groove OSB for roof sheathing?
Tongue & Groove Boards T&G roof decking, however, looks classy and rich. In fact, T&G boards are most frequently used when the sheathing is visible from the inside such as in cathedral ceilings or in some cabin-style homes, especially if the span of the rafters is greater than 2 feet.
How much is a sheet of roofing plywood?
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.
What grade of plywood is used for roof sheathing?
1/2 or 3/4-inch Plywood for Roof Sheathing? – Traditionally, 1/2-in CDX plywood was common choice with 24-in rafter spacing. However, heavier roof loads may require the use of 3/4-in CDX plywood for roof sheathing. Roofs with less pitch often carry heavier loads, including snow and ice accumulations in the winter.
Can you put plywood over plywood on roof?
The new plywood will have to be nailed to the rafters or roof trusses. But, with the old plywood left in place, it will be considerably more difficult to locate the rafters to ensure proper nail placement.
What’s better plywood or OSB?
Osb is stronger than plywood in shear. Shear values, through its thickness, are about 2 times greater than plywood. This is one of the reasons osb is used for webs of wooden I-joists.
What thickness of OSB do you use for roofing?
Standard roof sheathing thickness is ½” to ⅝” thick. If you are using OSB for your roof deck, then ⅝” is the recommended thickness. For plywood, which is slightly stronger than strand board, ½” thick is appropriate. Another factor is how far apart your trusses or rafters are spaced.
Which side of OSB goes up on roof?
OSB roof panels should always be installed with the grade stamp facing into the attic and the screened surface (with the nail guide lines) facing up. When the grade stamp is covered by roofing, the building inspector will not be able to confirm that the correct OSB roofing panel was used.
What thickness plywood should I use for shed roof?
Most builders use 15/32 CDX for the roof; it is an exterior-grade plywood with a thickness just under 1/2 inch. The floor needs to be more solid than the roof to support lawn maintenance equipment and people. Use sturdy, 3/4-inch-thick exterior plywood for the floor.
What is the best way to waterproof plywood?
Yes, you can make plywood waterproof by spraying it with liquid latex, waterproof paint, or varnish. You can also coat it with epoxy sealant or hard-drying oil to seal it and make it impervious to water.
How many sheets of plywood do you need for a roof?
Divide the total roof area by 32 to get the number of sheets you will need to cover the roof. A typical 4 foot by 8 foot sheet of plywood covers 32 square feet. If your roof area is 1,600 square feet, 1,600 divided by 32 will mean you need about 50 sheets to cover the roof.
Which is cheaper plywood or OSB?
OSB is less expensive than plywood. To build a typical 2,400-square foot home, OSB may cost $700 less than plywood. OSB is considered by many to be a “green” building material because it can be made from smaller-diameter trees, such as poplars, that are often farmed.
What do roofers put on the roof before they nail the shingles down?
Start by laying roof deck protection, or shingle underlayment, over the decking (plywood/OSB). Then, install new flashing (metal flashing is often called “drip edge” along the bottom of the roof near your gutters) and starter shingles at the edges. Nail the drip edge in place using your hammer and roofing nails.
Can you roof over tongue-and-groove?
Tongue and groove roof decking, especially the one from solid wood boards, is one of the two most common choices for residential use right now. The other one is plywood. In this article, we are going to discuss roof decking with T&G style from solid wood specifically.
