Roof Rafter Size Span

Floor joists ceiling joists rafters snow load rafters roof live load deflection limit.

Roof rafter size span.

1 ft 0 3048 m. 2 are indicated below. 1 psf lb f ft 2 47 88 n m 2. Rafter and joist span faq the lengths and sizes of joists vary depending on the species and quality of the lumber used.

Input the rafter span on the flat eave overhang and pitch of the roof. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. 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. Dead load weight of structure and fixed loads 15 lbs ft 2.

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. Input the rafter span on the flat eave overhang and pitch of 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. 2x4 2x6 2x8 2x10 2x12.

Live load is weight of furniture wind snow and more. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. This calculator is to be used as an estimating tool only. This calculator is to be used as an estimating tool only.

Click the button to calculate the stock size needed for this job. 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. Rafter stock size calculator. Live load 20 lbs ft 2 956 n m 2.

Rafter stock size calculator. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. It is always better to have a large rafter rather than be concerned with a sagging roof. Click the button to calculate the stock size needed for this job.

Includes result for hip valley factor slope factor and the roof slope in degrees. 3 stud construction standard utility. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. L 720 l 600 l 480 l 360 l 240 l 180.

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. Spacing in 12 16 19 2 24.