Floor Joist And Beam Spans

Surveyors and structural engineers use data from tables below to help calculate the size of timbers necessary to give adequate support to timber floors.

Floor joist and beam spans.

The floor joist spacing is the distance between the centers of any two installed joists. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Spans of timber joists in suspended timber ground floors. So we now have adequately sized floor joists and an adequately sized floor joist beam for our 24 x 13 house.

The ontario building code spans for joists rafters and beams 9 23 4 2. Our floor joist beam can span a maximum of 13. In the table above the widest floor beam span for 12 of supported floor joists is 14 7 if using a 5 ply 2 x 12. Beam and joist span tables built up wood floor beams supporting one floor in a house maximum spans for uniformly distributed loads species and grade supported built up beam size joist length 3 2x8 4 2x8 3 2x10 4 2x10 3 2x12 4 2x12 8 9 8 11 2 11 10 13 8 13 8 15 10 10 8 8 10 0.

See the image below for an example of joists spaced 16 on center 16 o c. Try our interactive span checker to find the posi joist suitable for your project. Other span tables are based on the guidance given in bs 5268 7 1 which is a uniformly distributed load of 1 5kn m for spans greater than 2400 mm and 3 6 kn load per metre width of floor for spans less than 2400 mm to ensure that very small joist sizes do not result from the calculations for smaller spans. True floor joist span calculations can only be made by a structural engineer or contractor.

Simplified span tables for southern pine lumber and glued laminated timber glulam headers beams and girders. Since the example house we are designing for is 12 feet wide we need to find in the floor joist span table a joist size and centering that can span 12 or wider. Spans for joists rafters and beams 1 except as required in sentence 2 and article 9 23 13 10 the spans for wood joists and rafters shall conform to the spans shown in tables a 1 to a 7 for the uniform live loads shown in the tables. This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction.

View joist rafter tables. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. View size selection tables. 2 spans for floor joists that are not selected from tables a 1 and a 2 and that.

Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.