Roof Sheathing Material Thickness

Several factors must be considered when determining appropriate roof sheathing thickness such as the.

Roof sheathing material thickness.

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. Minimum thickness most roofs will be sheathed in plywood at least 3 8 inch thick. For information on large panelized roof systems refer to the commercial construction application section. It also holds roofing nails well.

Common roof sheathing applications and installation recommendations are described in the related publications listed at right. You would go to table r503 2 1 1 1 to determine minimum nominal panel thickness. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. As per code in my area ottawa canada i plan on using 3 8 plywood for sheathing.

Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood. And for wood structural panel sheathing r803 2 2 allowable spans. Malcolm i almost always use 5 8 zip sheathing on roofs and metal roofing installers have never questioned it. Loads will vary with the.

Comes in standard 4 by 8 foot sheets is strong durable and relatively light. Cdx works fine in 1 2 or 5 8 thickness. Roof sheathing attaches to the surface of the rafters or trusses to form the structural skin of the roof. Required sheathing thickness for roofing important factors.

The common grade of plywood for roof sheathing is cdx. Steeper roofs tend to have thinner sheathing due to not much weight being applied to the roof while flat and low sloop roofs that are likely to gather weight from precipitation or people walking on it. I ve never used commodity osb on a roof but it s probably fine in 5 8 thickness and possibly in 1 2 thickness. According to 2009 irc table r803 1 minimum thickness of lumber roof sheathing.

Unlike with plywood siding the plywood sheet to be used for sheathing should be at least 3 8 inch thick. Correct installation of roof sheathing will ensure the best performance and help reduce complaints and callbacks. I just read somewhere actually in taunton press roofing with asphalt shingles book that one should consider using sheathing thicker than code to avoid sagging between rafters. The roof covering will be asphalt shingles.

Sheathing comes in different thicknesses and what type of roof you have will help designate what type of thickness you need. If you re in search of quotes for a roof sheathing job improvenet can put you in touch with up to four local contractors for free. Many code requirements are not inspected. That s considered to be the minimum.