Typical Roof Rafter Spacing

Rafter span tables use these two tables for roof rafters with a slope of 3 in 12 or less.

Typical roof rafter spacing.

For standard shed roof rafter spacing see rafter span chart. The most common rafter spacing is 24 inches and 5 8 inch plywood is recommended for that. Use these two tables for roof rafters with a slope greater than 3 in 12. Spans for joists greater than 20 feet that are parallel to the rafters require a 12 inch joist spacing when using 2 inch by 10 inch 2 douglas and hemlock fir or southern pine or 16 inch spacing when using 2 inch by 10 inch 2 douglas fir or southern pine.

The above spans are based on american softwood lumber standard sizes. Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. Plasterboard on the underside of the rafter. It is always better to have a large rafter rather than be concerned with a sagging roof.

In the us they are typically spaced at fractions of the roof sheathing size. It will support roof loads for most situations and is the standard for most roof applications. Builders aren t bound by standard rafter spacing measurements. There is no standard spacing it depends on what size of rafters you want to use and the span of your shed.

For instance 2 grade 2x4s at 16 on center will span just over 9. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Usually 400 450 or 600mm but any value can be used up to 610mm max are there any brittle finishes e g. But they do tend to space rafters in one of several industry standard increments typically either 12 16 or 24 inches apart.

In california 16 is by far the most common for residential construction. This is the distance between rafter centres. Rafter spacing depends on the roofing panel size.