Old Roof Rafter Size

Input the rafter span on the flat eave overhang and pitch of the roof.

Old roof rafter size.

There is no standard spacing it depends on what size of rafters you want to use and the span of your shed. This calculator is to be used as an estimating tool only. For instance 2 grade 2x4s at 16 on center will span just over 9. For standard shed roof rafter spacing see rafter span chart.

If you re building rafters and aren t sure where to start when determining the length of your lumber you re in the right place our rafter stock size calculator shows you how long your rafters should be so you ll know what you need in terms of framing lumber dimensional lumber studs and more. 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. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. If you get premium kiln dried lumber then you could span 10 5 with the same size of lumber and rafter spacing.

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.