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).

If the lumber used is of a lesser grade than 2. Generally, a 2×6 of 2 Grade southern yellow pine can span up to 6’ 0 if it is used as a joist and the total load on it is less than 25 lbs/sqft. 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. The maximum span of a 2×6 board for a lean to structure depends on the load the structure needs to support and the species of the lumber. For the 10×10 lean to shed roof that was constructed as the example for this article, the following rafter spacing was used. However, you want to make adjustments as needed to ensure that the edges of your plywood roof decking will land in the center of a roof rafter. While a 2×6 might be nearly double the cost of a 2×4, you can likely space the 2圆s further apart, negating the added expense of increasing your lumber width. Roof rafters are typically spaced 12 or 16 O.C. It includes the rise and works in feet and inches or metric values. 2×6 shed roof rafters are enough for nearly any type of shed a homeowner wants to build. 4) Select rafter spacing and width: Rafter spacing (and roof length) will be used to determine quantity of rafters needed for your project. If your roof pitch is in degrees, use our roof pitch calculator to convert degrees to pitch value.

Purlins shall be sized no less than the required size of the rafters that they support. Calculate the length of lean to shed roof rafters for any common roof pitch when the top of the rafters stop into a wall. Example: If your roof rises 5 for every 12 of run, enter 5 as roof pitch. 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