Osb Vs Cdx For Roofing

An inspector once told me that osb is stronger laterally while cdx is stronger vertically.

Osb vs cdx for roofing.

Cdx is best for sub flooring. Many home builders construct houses with osb for the entire roofdeck or sometimes they use cdx around the perimeter edges and osb in the center. Oriented strand board osb combines wood chips glue and resin into the shape of a sheet of plywood and bakes them together. It works fine for interior walls but i don t recommend it as a roof deck at all.

Although osb typically offers a higher shear rating which adds rigidity to your structure. It is also used for roof sheathing. Cdx and osb are used for almost similar things but because they have different features one is better applied in some tasks and the other one on other tasks. 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.

It is often less expensive than cdx plywood because this manufacturing process doesn t require the same costly veneers found on the front and back of cdx plywood. Osb is far less likely to expand and contract when exposed to humidity and moisture even though it will take longer to dry. When you count sub floors roofs and wall sheathing osb claims about 70 of the wood sheathing market in north america over plywood. With wrapping though it can withstand the elements without issue.

What if my house currently has an osb roofdeck. My personal opinion is that osb performs well on the wall and floor but stick to cdx plywood on the roof. One of the nice things about plywood is the variety of options you can buy. My personal opinion is that osb performs well on the wall and floor but stick to cdx plywood on the roof.

Consider having the osb replaced with cdx when your roof is replaced. New homes will usually see a few rainfalls before a roof is on and as. As a roofing contractor in seattle i strongly recommend that osb is never used as a roofdeck. Odds are that if you pass a housing development of wood framed houses it will have osb oriented strand board as exterior sheathing.

Far too often i see osb sag between the trusses making your roof look wavy. Although some people will ultimately choose cdx many experts argue that osb is better overall for roofing. In such places it does not get in contact with a lot of moisture which prevents it from getting damaged. Although osb typically offers a higher shear rating which adds rigidity to your structure.

To me lateral stregnth is more important studs carry the load down to the foundation not the plywood.