How Thick Is Roof Decking

Many factors affect thickness.

How thick is roof decking.

Plank sheathing usually 1 6 or 1 8 was used as a roof deck before plywood. Standard structural decking patterns are 2 nominal tongued and grooved t g and 3 and 4 double t g products available with vee or eased edges to meet discriminating architectural requirements. 8d ring shank nails should be used instead. Roof sheathing standard roof sheathing which consists of 4 by 8 sheets of plywood or oriented strand board or osb is 1 2 inch thick and attaches directly to the roof rafters or the roof trusses.

Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. What is plank sheathing. Osb roof decking thickness 7 16 1 2 or 5 8. For example a 26 gauge steel panel can range between 0 0179 and 0 0217 inches thick according to a university of north carolina at chapel hill resource.

Keep the 16 oc go with 1 2 osb and add an extra clip in each space. The thickness of plywood used for roof decking depends on the roof slope the spacing of. The typical thickness range for sheathing is 3 8 to 3 4 inch. When it s too thin.

In this case you can t use a 3 8 inch thick sheet. Most roofs are spaced at least 20 inches apart. An exception to this standard however may occur if you intend to install slate concrete or tile shingles on your roof. Plywood is made with three or more layers of thin wood glued together with the grain.

If the plywood thickness is less than or the osb less than 7 16 it is going to be weak with the roof rafters spaced the standard 2 on center. Thickness of a steel roof deck can be determined at a roof hatch where the edge of the deck may be available for measurement with a micrometer. For this you can either go for a half inch or 5 8 inch thick sheet. Sheathing should be a minimum of 19 32 inch thick.

In that case a pullout test device can confirm adequacy. Flexural strength can be assumed to be 33ksi unless a new single ply system is contemplated that requires a higher pull out strength. Structural decking also known as roof decking should not be confused with lumber intended for residential and non residential outdoor decks.