Osb Sheathing Thickness For Roofs

That in a nutshell is the one big advantage plywood holds over osb.

Osb sheathing thickness for roofs.

Plywood s advantage over osb. Thermostat 7 16 cat ps2 10 osb sheathing application as 4 x 8. Using osb osb comes in 4 by 8 foot sheets as does plywood but the manufacturing process allows the production of longer and wider ones. Panel thickness will also affect permeability using the 2 perm variable of 7 16ths osb sheathing at 3 4 thickness the permeability drops to 2 3rds of a perm.

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. The most common rafter spacing is 24 inches and 5 8 inch plywood is recommended for that. Keep in mind that the load of the roof still plays a role in the plywood thickness. Many homes have rafters that are even wider at 24 inches apart and will require a thicker sheet of plywood.

With edge support and the same snow load 3 8 inch osb can be used. Thicknesses range from 5 16 to 3 4 inch and the proper one. 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. A flatter roof with rafters farther apart may need a thickness of up to inch.

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. It will support roof. 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. When this is the case experts recommend a 5 8 inch thick sheet.

For rafters spaced 20 or more inches apart 1 2 or 5 8 inch plywood is recommended. Osb is widely used as roof decking material. For pricing and availability. Osb sheathing 15 32 cat ps2 10 osb sheathing application as 4 x 8.

The thickness required by josh s circumstances are good for roof snow loads of up to 70 psf again spanning 24. 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. A homeowner recently wrote and asked me the following regarding osb roof decking.