Roof Rafter Span Sizes

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

Roof rafter span sizes.

Here the number is 941 86 inches. 2 are indicated below. Usually 400 450 or 600mm but any value can be used up to 610mm max. Live load is weight of furniture wind snow and more.

Here the number is 1166 66 inches. Rafter and joist span faq the lengths and sizes of joists vary depending on the species and quality of the lumber used. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. This sizing guide for roof rafters will help determine what you need for your small project.

Click the button to calculate the stock size needed for this job. 1 ft 0 3048 m. Click the button to calculate the stock size needed for this job. Live load 20 lbs ft 2 956 n m 2.

Publications calculators software building codes fire safety span tables decks weights and measurement codes standards calculators software. Dead load weight of structure and fixed loads 15 lbs ft 2. 1 psf lb f ft 2 47 88 n m 2. Rafter stock size calculator.

Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. This is the distance between rafter centres. 1 in 25 4 mm.

This calculator is to be used as an estimating tool only. There are several variables to consider when determining the proper rafter size. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Rafter run outer wall this should be measured starting from the center of the roof span and then extending to the very edge of the exterior wall.

This calculator is to be used as an estimating tool only. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.