The braces shall be spaced not more than 4 feet (1219 mm) on center and the unbraced length of braces shall not exceed 8 feet (2438 mm). To determine the final size of a rafter, consider various factors such as loads, wood species, wood grade, the slope of a roof, and the location of the rafter. Any thoughts Oh and wasnt planning on adding sheathing obviously. Rafters are 2圆 and span a little over 60' from wall to 2x8 ridge board. But got to thinking I probably dont need to space them that close. I was just planning on runnin rafters at 24 o.c. For roofs that will experience heavy snow or wind and will.

Purlins shall be continuous and shall be supported by 2-inch by 4-inch (51 mm by 102 mm) braces installed to bearing walls at a slope not less than 45 degrees (0.785 rad) from the horizontal. Im installing 36' exposed fastener steel panels on a treehouse. For roofs that wont experience heavy snow loads, a gable roof can span up to 22 with 2×4 rafters.Purlins shall be sized no less than the required size of the rafters that they support. Installation of purlins to reduce the span of rafters is permitted as shown in Figure R802.5.1.

Rafter spacing for metal roof on lean