Flat Roof Joist Span

Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.

Flat roof joist span.

For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Joist spacing of 24 inches is allowed for spans between 16 to 20 feet using 2 inch by 10 inch lumber of these three grades. 1 ft 0 3048 m. Live load 20 lbs ft2 956 n m2 maximum span ft in nominal size.

Usually 400 450 or 600mm but any value can be used up to 610mm max 1 2 timber strength class and joist size automatically calculate sizes suitable for supporting the loads below. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Maximum slop3 10 deg. 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.

Live load is weight of furniture wind snow and more. Span is clear span between supports. Use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size. 1 psf lbf ft2 47 88 n m2.

Permissible clear spans for flat roof joists to bs 5268 7 2 imposed load. Roof rafter span use this table to determine the maximum lengths of roof rafters based on species and grade of lumber spacing dimensions load and slope. Find the column for your dead load and spacing and the row for your timber size to find the permissible clear span in metres. This is the distance between joist centres.

Joist breadth 47mm. Also available for the android os. Supporting imposed load for access and repair only. Floor joists flat roof joists assumptions at 400mm centers supporting permanent load excluding self weight of joists up to 50kg m2.

Dead load weight of structure and fixed loads 15 lbs ft2. View joist rafter tables. 1 in 25 4 mm. At least 40mm bearing on supports.

Span calculator for wood joists and rafters also available for the android os.