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Sheathing Thickness The typical thickness of roof sheathing is about 7/16-inch, which is just under 1/2-inch.
What is the best thickness for roof sheathing?
The recommended thickness for roof sheathing is ⅝” thick. Sheathing with a thickness of less than that is much more likely to result in bowing between framing which could potentially compromise your exterior roof material.
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 size sheathing should be used for roofing?
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. Steeper roofs will have lighter loads per square foot.
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.
What size should roof decking be?
Roof sheathing comes in grid-marked 4-by-8-foot sheets, and should be installed perpendicular to the frame. Sheathing should be a minimum of 19/32-inch thick. Never attach roof sheathing with staples; 8d ring-shank nails should be used instead. The typical thickness range for sheathing is 3/8 to 3/4 inch.
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 plywood is used for roof sheathing?
CDX Plywood A special grade of plywood called “CDX” is a popular choice for roof sheathing. No, the “X” in CDXplywood does not stand for “exterior.” Rather, it references the kind of glue used to bond the layers of veneer together. CDX plywood can withstand temporary exposure to rain and other moisture sources.
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.
Can 7/16 OSB span 24 inches?
Wall panels 7/16 Category may be used on studs spaced up to 24” o.c. LP OSB sheathing panels are designed for use in roof, wall and subfloor systems in commercial and residential projects, maintenance, remodeling or new construction. OSB sheathing panels comply with the following industry standards and certifications.
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.
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.
Is OSB OK for shed roof?
For an inexpensive, value option 9mm OSB can be used for your garden shed roof. Start by fitting the beam across the top of the shed, slotting it into the pre-cut grooves at the top of the two pointed ends on an apex shed (known as the gable ends).
How thick should plywood be for a shed roof?
Plywood thicknesses for roofs start at 3/8” in areas with light load requirements on rafters at 16” centers. Thicknesses of 1/2 to 5/8 inch are common with rafters spaced at 24” centers. For heavy load rated areas, 3/4-inch-thick plywood is recommended, regardless of rafter spacing.
What is CDX plywood used for?
CDX Plywood is used primarily by contractors to build exterior walls and roofs. CDX plywood has one side veneer grade “C” and one side veneer grade “D”. The two are bonded together with glue which can withstand a little moisture. The APA would recognize CDX Grade Plywood as C-D Exposure 1 plywood.
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.
What is RTD plywood used for?
Exterior panels sometimes referred to as RTD sheathing, are designed to hold up to constant moisture. They are completely waterproof and are great for installing in places where you expect consistent exposure to moisture. This RTD sheathing is great for roofs and other outdoor applications.
What 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.
