Rafter Sizes For A Pitched Roof

Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings.

Rafter sizes for a pitched roof.

This calculator is to be used as an estimating tool only. Rafter stock size calculator. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Again make sure to consult local codes.

An spf roof at the same spacing and lumber size will span 11. Rafter span tables use these two tables for roof rafters with a slope of 3 in 12 or less. The above spans are based on american softwood lumber standard sizes. That means it can span a total length of over 26 for a gable roof.

You write the pitch assuming a run of 12 inches thus the ratio would describe how much a roof rises for each foot of the run. As aforementioned there is no standard pitch of a roof. Click the button to calculate the stock size needed for this job. Click the button to calculate the stock size needed for this job.

It is always better to have a large rafter rather than be concerned with a sagging roof. An syp 2 6 rafter at 24 o c. These numbers are for roofs supporting light loads of 20 pounds for square foot. Input the rafter span on the flat eave overhang and pitch of the roof.

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. Can span up to 13 4. Roof pitch between 30 and 45 degrees with rafter spacing strength class c24 maximum clear span of purlins in metres for roof pitches of between 30 and 45 degrees roof pitch between 30 and 45. Rafter stock size calculator.

Surveyors span tables for designing roof rafters. For pitched roofs flat roofs and ceiling joists. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. Area span on the flat.

Use these two tables for roof rafters with a slope greater than 3 in 12. Rafter length using angle v r 2cos a rafter length using pitch v r 2 sqrt 1 p 2 where v overhang r roof span p pitch use our online rafter length calculator to quickly compute the length of the shed roof rafter by entering the measurements of overhead length of roof span pitch or angle. How do you calculate the slope of a roof.