Osb Sheathing Thickness For Roofs

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

Osb sheathing thickness for roofs.

A homeowner recently wrote and asked me the following regarding osb roof decking. Thermostat 7 16 cat ps2 10 osb sheathing application as 4 x 8. For pricing and availability. 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 rafters spaced 20 or more inches apart 1 2 or 5 8 inch plywood is recommended. Keep in mind that the load of the roof still plays a role in the plywood thickness. For pricing and availability. Thicknesses range from 5 16 to 3 4 inch and the proper one.

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. Many homes have rafters that are even wider at 24 inches apart and will require a thicker sheet of plywood. 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. The most common rafter spacing is 24 inches and 5 8 inch plywood is recommended for that.

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. 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. Osb is widely used as roof decking material. The thickness required by josh s circumstances are good for roof snow loads of up to 70 psf again spanning 24.

It will support roof. 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. With edge support and the same snow load 3 8 inch osb can be used.

A flatter roof with rafters farther apart may need a thickness of up to inch. Plywood s advantage over osb. When this is the case experts recommend a 5 8 inch thick sheet.