Osb Under Flat Roof

This minimum will only work if the rafters are set 16 inches apart at most and if the roof doesn t have too much load.

Osb under flat roof.

Adding osb is good when one is going to install insulation. I m planning on building a pole barn using 3 1 2 inch schedule 40 pipe as my frame. A homeowner recently wrote and asked me the following regarding osb roof decking. This minimum wouldn t work if you have a flat roof.

Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood the most popular being osb. Thicknesses range from 5 16 to 3 4 inch and the proper. When you count sub floors roofs and wall sheathing osb claims about 70 of the wood sheathing market in north america over plywood. Odds are that if you pass a housing development of wood framed houses it will have osb oriented strand board as exterior sheathing.

Osb is widely used as roof decking material. That s considered to be the minimum. Rafters that are slightly farther apart might require inch or 5 8 inch thick plywood. 5 thoughts on osb under steel roofing on pole buildings kamel may 3 2018 at 11 22 am.

Mike the pole barn guru. 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 roof that lays practically flat will have a much heavier load than a steeper roof that allows rain snow and ice to roll right off. However you may need to consider bolstering the plywood thickness for a roof that has a higher load.

Osb comes in 4 by 8 foot sheets as does plywood but the manufacturing process allows the production of longer and wider ones. 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. Osb and plywood come in thicknesses ranging from 5 16 to 3 4 inch and the thickness needed for a particular roof depends on several factors including rafter spacing expected load and roof design. I found some pre made 4 inch pipe trusses.

Most roofs are spaced at least 20 inches apart. This prevents thermal changes and will reduce condensation. With edge support and the same snow load 3 8 inch osb can be used.