Osb Thickness For Roof

The miami dade county board of county commissioners banned osb for use as roof sheathing after hurricane andrew destroyed thousands of homes in 1992.

Osb thickness for roof.

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. A viable alternative to plywood this osb board is engineered to prevent any cupping warping or splitting. Oriented strand board osb is a material with high mechanical properties that make it particularly suitable for load bearing applications in construction. 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.

For heavier loads a 40 20 rated panel 19 32 or 5 8 will support a 130 psf live load and 48 24 rated panels 23 32 or are good to175 psf. The roof of a riding arena made with strong panels consisting of 18mm thick swiss krono osb f. Osb comes in 4 by 8 foot sheets as does plywood but the manufacturing process allows the production of longer and wider ones. A homeowner recently wrote and asked me the following regarding osb roof decking.

When this is the case experts recommend a 5 8 inch thick sheet. 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. 25mm thick swiss krono osb 3 as a walkable subroof surface. Oriented strand board commonly referred to as osb is a type of engineered lumber similar to particle board formed by adding adhesives and then compressing layers of wood strands.

Keep in mind that the load of the roof still plays a role in the plywood thickness. This riding arena was built using swiss krono osb f 15mm thick for the roof and 18mm thick for the walls. A flatter roof with rafters farther apart may need a thickness of up to inch. Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood the most popular being osb.

The thickness required by josh s circumstances are good for roof snow loads of up to 70 psf again spanning 24. Thicknesses range from 5 16 to 3 4 inch and the proper one to use. Osb is widely used as roof decking material. Many homes have rafters that are even wider at 24 inches apart and will require a thicker sheet of plywood.

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.