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.
Floor joist and beam spans.
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.
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.
You will be given a range of depths and centres that are available and also an indicative deflection result.
View size selection tables.
View joist rafter tables.
Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.
The ontario building code spans for joists rafters and beams 9 23 4 2.
Spans of timber joists in suspended timber ground floors.
Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.
2 spans for floor joists that are not selected from tables a 1 and a 2 and that.
Try our interactive span checker to find the posi joist suitable for your project.
So we now have adequately sized floor joists and an adequately sized floor joist beam for our 24 x 13 house.
Simplified span tables for southern pine lumber and glued laminated timber glulam headers beams and girders.
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.
True floor joist span calculations can only be made by a structural engineer or contractor.
The floor joist spacing is the distance between the centers of any two installed joists.
Our floor joist beam can span a maximum of 13.
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.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.
See the image below for an example of joists spaced 16 on center 16 o c.
