How Thick Should Osb Be For Roofing

You need to find a sheathing with a span rating of at least 32 16 which means either 15 32 or 1 2 thick osb.

How thick should osb be for roofing.

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. For the curious 7 16 osb has a span rating of 24 16 and with supports every 24 inches is good for a roof live load of 40 psf pounds per square foot with a 10 psf dead load. With this thickness any deflection under dead loads only the weight of materials only should prove to be imperceptible. Loads will vary with the.

We re in dallas so we don t engineer for tremendous live loads for an asphalt shingle and we feel comfortable with 16 oc rafter spacing and 7 16 osb decking. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. An exception to this standard however may occur if you intend to install slate concrete or tile shingles on your roof. Thicknesses range from 5 16 to 3 4 inch and the proper one to use.

Standard roof sheathing which consists of 4 by 8 sheets of plywood or oriented strand board or osb is 1 2 inch thick and attaches directly to the roof rafters or the roof trusses. Osb roof decking thickness 7 16 1 2 or 5 8. Osb is lightweight relatively inexpensive and strong enough to resist bending or breaking should someone walk on the roof. With edge support and the same snow load 3 8 inch osb can be used.

Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood the most popular being osb. Minimum thickness most roofs will be sheathed in plywood at least 3 8 inch thick. Osb comes in 4 by 8 foot sheets as does plywood but the manufacturing process allows the production of longer and wider ones. Plywood is a bit more expensive but is usually stronger and is often selected in cases where the roof covering is heavier such as for slate clay or concrete tile roofs.