Roof Decking Thickness Osb

Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood the most popular being osb.

Roof decking thickness osb.

With edge support and the same snow load 3 8 inch osb can be used. Common roof sheathing applications and installation recommendations are described in the related publications listed at right. Osb roof decking thickness 7 16 1 2 or 5 8 currently we space rafters 16 oc and use 7 16 osb with h clips. 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.

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. A homeowner recently wrote and asked me the following regarding osb roof decking. Roof sheathing thickness unlike with plywood siding the plywood sheet to be used for sheathing should be at least 3 8 inch thick. Plywood and oriented strand board osb are used in roof sheathing systems ranging from simple single family residences to large commercial buildings.

A flatter roof with rafters farther apart may need a thickness of up to inch. That s considered to be the minimum. Correct installation of roof sheathing will ensure the best. Thicknesses range from 5 16 to 3 4 inch and the proper one to use.

Many homes have rafters that are even wider at 24 inches apart and will require a thicker sheet of plywood. Osb is widely used as roof decking material. Loads will vary with the pitch of the roof. Osb comes in 4 by 8 foot sheets as does plywood but the manufacturing process allows the production of longer and wider ones.

Keep in mind that the load of the roof still plays a role in the plywood thickness. Osb panel products give engineers designers specifiers and builders a broad array of choices for use as subfloors combination floors wall and roof sheathing. Oriented strand board osb is commonly used as the primary structural sheathing component in residential construction and low rise commercial applications. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads.

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.