Osb Vs Cdx For Roofing

My personal opinion is that osb performs well on the wall and floor but stick to cdx plywood on the roof.

Osb vs cdx for roofing.

New homes will usually see a few rainfalls before a roof is on and as. 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. An inspector once told me that osb is stronger laterally while cdx is stronger vertically. Osb is far less likely to expand and contract when exposed to humidity and moisture even though it will take longer to dry.

Odds are that if you pass a housing development of wood framed houses it will have osb oriented strand board as exterior 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. One of the nice things about plywood is the variety of options you can buy. Far too often i see osb sag between the trusses making your roof look wavy.

Oriented strand board osb combines wood chips glue and resin into the shape of a sheet of plywood and bakes them together. 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. Cdx is best for sub flooring. Although osb typically offers a higher shear rating which adds rigidity to your structure.

Although some people will ultimately choose cdx many experts argue that osb is better overall for roofing. To me lateral stregnth is more important studs carry the load down to the foundation not the plywood. Far too often i see osb sag between the trusses making your roof look wavy. Consider having the osb replaced with cdx when your roof is replaced.

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 works fine for interior walls but i don t recommend it as a roof deck at all. My personal opinion is that osb performs well on the wall and floor but stick to cdx plywood on the roof. It is also used for roof sheathing.

In such places it does not get in contact with a lot of moisture which prevents it from getting damaged. Over the years i have seen claims for plywood decking delaminating which can cause squeeks and knocks between the ply s. Although osb typically offers a higher shear rating which adds rigidity to your structure. What if my house currently has an osb roofdeck.

As a roofing contractor in seattle i strongly recommend that osb is never used as a roofdeck.