Shed Roof Joist Sizes

Flat roof joist calculator.

Shed roof joist sizes.

To size joists and rafters use the maximum span tables for southern yellow pine. Boarding to be fastened on top of flat roof joists with a depth to width ratio greater than 4 the allowable clear spans have been calculated in accordance with bs 5268 2 2002 structural use of timber part 2. Code of practice for permissible stress design materials and workmanship and bs 5268 7 2 1989 structural use of timber section 7 2. There is no standard spacing it depends on what size of rafters you want to use and the span of your shed.

What is the standard shed roof rafter spacing. In other words if there is a 1 1 2 ridge board nailed into the wall and the width of the lean to is 96 then the run will be 94 1 2 96 1 1 2 94 1 2. For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.

More roof calculators roof truss calculator. The lengths and sizes of joists vary depending on the species and quality of the lumber used. Enter this measurement into the calculator and select a roof pitch and the length of the rafter will automatically returned along with the rise. Trying to find what size lumber to use.

In addition this calculator will also allow you to calculate the total number of floor joist needed to complete your shed based on the measurements you provide. The full version allows any size. 1 enter joist details 1 1 span and joist spacing. This demo version is fixed at 1m clear span.

If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. It is always better to have a large rafter rather than be concerned with a sagging roof. For instance 2 grade 2x4s at 16 on center will span just over 9. This rafter span calculator is species specific for douglas fir hemlock etc.

This is based upon the span of the rafter horizontal span not total rafter length live and dead loads. Enter a specific joist size 2 loadings dead load.