However osb is generally considered less resistant to water it swells in thickness when exposed to moisture and some people prefer plywood for roofs and subfloors.
Is osb good for roof.
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.
But still no one will blame you if you choose plywood over 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.
Up until 2000 plywood held the majority of the market for wall roof and floor sheathing when it was surpassed by osb which as of 2018 held about 75 of the market share.
Both plywood and osb are used for sheathing roofs walls and subfloors they work equally well for these uses are just as easy to drill into and have equivalent ability to hold nails.
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.
In 2001 oriented strand board surpassed plywood in terms of square footage produced.
New homes will usually see a few rainfalls before a roof is on and as noted above osb doesn t handle moisture well.
Suitability for roof sheathing.
Both the national roofing contractors association and the asphalt roofing manufacturers association recommend the use of osb for roof sheathing as long as it bears.
A homeowner recently wrote and asked me the following regarding osb roof decking.
Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood the most popular being osb.
While plywood remains a good and viable option the fact remains that osb is now the preferred choice.
With edge support and the same snow load 3 8 inch osb can be used.
In the case of a subfloor deformations left in the osb after it dries can lead to wavy flooring.
One of the nice things about plywood is the variety of options you can buy.
Despite its common use as such we don t recommend using osb for subfloors but that s really just for aesthetic reasons.
Building codes the engineered wood association architects and most builders rate plywood and oriented strand board obs sheathing equal in strength and durability.
It has been estimated that osb has a stronghold of of the market share mainly because it s the more affordable option.