Required Thickness Of Roof Sheathing

Loads will vary with the.

Required thickness of roof sheathing.

Minimum thickness most roofs will be sheathed in plywood at least 3 8 inch thick. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Sheathing type typically 15 32 inch or thicker panels are required in high wind areas. Sheathing should be a minimum of 19 32 inch thick.

Roof sheathing panel spacing hints. Comes in standard 4 by 8 foot sheets is strong. Building codes for roofing reqiure a minimum 1x4 and the spaces between battens should not exceed 3 1 2 inches figure 2 46 wood shingles over spaced sheathing and figure 2 47 wood shakes installed over wood sheathing are illustrated below. Use a 10d box 0 128 inch by 3 inch nail as a spacer to gauge 1 8 inch edge and end spacing between panels.

Oriented strand board osb or plywood can be used although plywood will provide higher nail head pull through resistance. 8d ring shank nails should be used instead. Many code requirements are not inspected. And for wood structural panel sheathing r803 2 2 allowable spans.

The apa table has a span rating for the sheathing installed with or without h clips and the span rating is the same both ways. And if you re still wondering what roof sheathing is and what materials are typically used read on and satisfy your curiosity. For the most common roof sheathing in our area which is 1 2 nominal 7 16 actual sheathing over trusses or rafters at 24 on center there is no requirement for h clips. Use panels rated as exposure 1 or better.

You would go to table r503 2 1 1 1 to determine minimum nominal panel thickness. According to 2009 irc table r803 1 minimum thickness of lumber roof sheathing. Panel edges shall have approved tongue and groove joints or shall be supported with blocking unless 1 4 inch minimum thickness underlayment or 1 1 2 inches of approved cellular or lightweight concrete is placed over the subfloor or finish floor is 3 4 inch wood strip. The typical thickness range for sheathing is 3 8 to 3 4 inch.

Never attach roof sheathing with staples.