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Minimum Thickness 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.
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 kind of plywood is best for roofing?
Exterior Plywood is the preferred material for roofing. It also performs well when exposed to moisture over long periods of time. The price is low compared to other roofing materials and the installations are also easy.
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.
What thickness OSB should be used 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.
What is better for roofing OSB or plywood?
Plywood Holds the Moisture Advantage Over OSB When plywood gets wet, it tends to swell. OSB takes longer than plywood to get saturated, but also takes much longer to dry out. When used as roof sheathing, this tendency to hold moisture means it will degrade faster than plywood when exposed to chronic leaks.
Is CDX plywood good for roofing?
Moisture Differences In reality, CDX plywood can only withstand water for a short period of time. Do not use CDX for roofing, sheds, or other places that are exposed to moisture consistently. The sole exception to this is pressure treated CDX, which can survive for decades without even a protective coating.
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.
How thick should sheathing be?
The U.S. Department of Energy has determined that 7/16-inch sheathing is the minimum appropriate thickness for structural wall sheathing with an exception for gable end walls, where the minimum thickness is 3/8 inch.
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 far should roof sheathing overhang rafter tails?
Measure 45-3/4 inch up the rafter from the cut end of the truss tail and draw a line along the trusses. This is the upper edge of the first row of roof sheathing, with enough overhang to allow the sub fascia and fascia to tuck neatly underneath when the time comes.
Do you need H clips roof sheathing?
H-clips are referred to in the APA Guide as “edge support.” For the most common roof sheathing in our area, which is 1/2” nominal (7/16” actual) sheathing over trusses or rafters at 24” on center, there is no requirement for H-clips. One or two H-clips will often allow a longer span between roof trusses/rafters.
Which side of OSB goes down?
OSB also has stamping that reads “This Side Down”. This directs the worker on the correct orientation of the board when installing. The side with the stamp is the smoother side. When installed smooth side down, the rough surface will then face up and give the worker traction for safety.
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.
What type of wood is best for roofing?
Longevity. In terms of cost-savings, cedar wood is long-lasting, making it an ideal roofing material. Cedar lasts at least 10 years longer than common roofing materials, like asphalt shingles.
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.
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.
