Pitched Roof Rafter Spacing

Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches.

Pitched roof rafter spacing.

The spacing between rafters in a given building is part of the engineering calculations that determine the required structure of the roof. For standard shed roof rafter spacing see rafter span chart. Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16 size of rafters in mm 400mm 450mm 600mm. For roofs that will experience heavy snow or wind and will span the same distance use 2 6 rafters.

Surveyors span tables for designing roof rafters. If you get premium kiln dried lumber then you could span 10 5 with the same size of lumber and. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Other relevant factors include the type of wood being used for the rafters the size of the rafters and the load that the rafters need to support.

Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. Rafters must be strong enough to hold the roof sheathing and the shingles. There is no standard spacing it depends on what size of rafters you want to use and the span of your shed.

Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. If your local building authority has a rafter spacing code you may not space rafters wider than required by code. You can use either 2 6 or 2 4 rafters for roofs with a 3 12 pitch or greater but it depends on the overall size of your shed. For pitched roofs flat roofs and ceiling joists.

As a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. For instance 2 grade 2x4s at 16 on center will span just over 9. Our roof rafter calculator tools are handy for calculating the number of rafters needed rafter length calculator lineal feet of rafter board feed in ridge and sub facia and the total board feet in the roof. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.