Span Flat Roof Joist Wood

Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.

Span flat roof joist wood.

The full version allows any size. Span tables for flat roof joists to bs 5268 7 2 imposed loads of 0 75 kn m for maintenance and snow load are applicable where there is no permanent access no fixed ladder or staircase and most areas where the altitude does not exceed 100 metres refer to bs 6399 3. 1 ft 0 3048 m. Flat roof joist calculator.

Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. Dead load weight of structure and fixed loads 15 lbs ft 2. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. These span tables apply only to flat roof and roof with a slope of up to 10 degrees.

Live load is weight of furniture wind snow and more. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Usually 400 450 or 600mm but any value can be used up to 610mm max. 1 psf lb f ft 2 47 88 n m 2.

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. 2 are indicated below. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. 1 enter joist details 1 1 span and joist spacing.

Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. While every effort has been made to insure the accuracy of the information presented and special effort has been made to assure that the information reflects the state of the art neither the west coast lumber inspection bureau the american wood council nor its members assume any responsibility for any particular design prepared from this online span calculator. They are ideal for long spans including continuous spans over intermediate supports. Also available for the android os.

Because i joists are straight and true it s easier for builders to avoid crowning and maintain a level framing surface. This is the distance between joist centres. Common i joist applications i joists are used extensively in residential floor and roof framing. Span calculator for wood joists and rafters also available for the android os.