Both OSB and plywood panels can cut and installed on a roof using conventional roofing equipment. They have similar structural characteristics, and can be used interchangeably. ... OSB is now the most-used sheathing and subflooring material for new roofs and roof replacements.

What thickness OSB should be used for roofing?

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.

How long does OSB last for on roof?

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.

Is OSB OK in the rain?

Your framing lumber and the oriented strand board (OSB) are going to be fine. The glues used to make OSB are water-resistant because the manufacturers know that virtually no one can build a home that won't get wet before the roof and siding is applied. ... The OSB floors should be swept clean each day after work concludes.

How do you waterproof a OSB roof?

You just need to use a paintbrush to apply the waterproofing coat on the OSB pieces. Repeat applying it on each side. It will take about 12 to 14 hours for the waterproofing to dry. To ensure that the OSB is waterproof pour some water on the OSB piece and wait for a few hours.

Plywood vs OSB Roofing Debate | Roofing Insights | Roof materials

Can I waterproof OSB?

OSB is strong and water-resistant.

Every single fiber or piece of wood in an OSB is saturated with a cocktail of resins designed to provide superior strength and waterproofing to the finished product. ... This type of board is an excellent material for use in waterproofing systems, be they roof, sub-floor or wall.

How do you protect OSB from rain?

If you need to utilise Oriented Strand Board (OSB) to sheathe your shed's walls, then you would need to construct those walls like the walls of a house. This means you would need to use a moisture-resistant barrier over the OSB and then cover it with siding.

What type of OSB is used for roofing?

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 OSB last in rain?

OSB 3 is classified as resistant to humid conditions. This is a liability choice to avoid misunderstandings. We have had OSB 3, also in horizontal orientation, exposed to rain for at least 4 months.

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.

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.

Is OSB more water resistant than plywood?

OSB takes longer to get wet than plywood but also takes longer to dry out. When used as a roof sheathing, this tendency to hold moisture means it can degrade faster than plywood when exposed to chronic leaks. ... Swollen edges have been known to telegraph visible ridges called “ghost lines” through asphalt roof shingles.

Is OSB board better than plywood?

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. However, nail-holding ability controls performance in shear wall applications.

Can you put felt on a wet shed roof?

Roofing felt should ideally be dry when shingles are installed to avoid ripping, but it's still possible to install when wet. The felt can be damaged if exposed to moisture too long.

Is OSB cheaper than plywood?

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 should I use for roof sheathing?

Oriented Strand Board (OSB) or plywood can be used, although plywood will provide higher nail head pull-through resistance. Use panels rated as “Exposure 1” or better. Install sheathing panels according to the recommendations of the Engineered Wood Association (APA). Use panels no smaller than 4 feet long.

Do you need plywood under shingles?

Sometimes referred to as roof sheathing or a roof deck, this plywood acts as a foundation for the layers of underlay and the shingles on your roof and connects the roof to the frame of the house. Even though it isn't visible, it is very important to the structure of your home.

Is OSB good for exterior use?

OSB is highly resistant to moisture and can be water and weatherproofed for exterior use using good quality paint or stain. It has superior strength to other wood panels and a slower rate of moisture absorption. Properly maintained and protected, OSB will last for decades.

How do you make OSB last outside?

Soak the tip of your paintbrush in your sealer and begin brushing it over the surface and on the ends of the OSB pieces. Make sure you repeat this process on each side, not just where your cuts were made. Coat the pieces as they lay on the tarp, and then let the waterproofing sit to dry for 12 to 14 hours.

Is OSB board 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).

What do you cover OSB board with?

OSB's open strands readily absorb the paint, requiring two or three coats of primer to close up the pores. Older OSB will be incredibly porous, requiring several coats of paint plus primer. Particularly old OSB that is beginning to fall apart cannot be painted; the paint will not help glue the OSB together.

Can you use 7/16 OSB on a roof?

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.

Which plywood is best for roofing?

Most Common Thickness

The most common rafter spacing is 24 inches, and 5/8-inch plywood is recommended for that. It will support roof loads for most situations and is the standard for most roof applications. Roofs with very heavy loads may require 3/4-inch thickness.

What holds screws better OSB or plywood?

Plywood and OSB: Screw withdrawal or holding ability. Group 1 plywood, made from the strongest species of wood such as Southern Yellow Pine, holds screws better than OSB.