If you get premium kiln dried lumber then you could span 10 5 with the same size of lumber and rafter spacing.
Old roof rafter size.
Lumber size width 2x8 2x10 or 2x12 boards will be used to estimate cost of each rafter as well as total cost excluding local sales tax.
Rafter spacing and roof length will be used to determine quantity of rafters needed for your project.
For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2.
There is no standard spacing it depends on what size of rafters you want to use and the span of your shed.
Click the button to calculate the stock size needed for this job.
For standard shed roof rafter spacing see rafter span chart.
This calculator is to be used as an estimating tool only.
If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
Just enter the dimensions of the roof rise and run to get started.
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.