Tempo:
Table 21 Maximum spans for floor joists – special cases1, 2
Commercial Designation Douglas fir – larch (includes Douglas fir and western larch)
Grade No. 1 and No. 2
Hem – fir (includes western hemlock and amabilis fir)
No. 1 and No. 2
Spruce, pine, or fir (includes spruce [all species except coast sitka spruce], jack pine, lodgepole pine, balsam fir and alpine fir)
No. 1 and No. 2
Northern species (includes any Canadian species covered by the NLGA Standard Grading Rules)
No. 1 and No. 2
Joist Size, mm in. 38 x 140 2x6 38 x 184 2x8 38 x 235 2 x 10 38 x 286 2 x 12 38 x 140 2x6 38 x 184 2x8 38 x 235 2 x 10 38 x 286 2 x 12 38 x 140 2x6 38 x 184 2x8 38 x 235 2 x 10 38 x 286 2 x 12 38 x 140 2x6 38 x 184 2x8 38 x 235 2 x 10 38 x 286 2 x 12
Maximum Span, m (ft.–in.) Joists with ceilings Joists with attached to Wood Furring concrete topping Joist Spacing, mm (in.) Joist Spacing, mm (in.) With or Without Without Bridging With Bridging Bridging3 300 400 600 300 400 600 300 400 600 12 16 24 12 16 24 12 16 24 3.29 10-10 4.06 13-4 4.78 15-8 5.44 17-10 3.29 10-10 4.06 13-4 4.78 15-8 5.44 17-10 3.14 10-4 3.87 12-8 4.55 14-11 5.18 17-0 2.83 9-4 3.50 11-6 4.11 13-6 4.68 15-4
2.99 9-10 3.83 12-7 4.50 14-9 5.12 16-10 2.99 9-10 3.83 12-7 4.50 14-9 5.12 16-10 2.85 9-4 3.64 11-11 4.28 14-1 4.88 16-0 2.57 8-5 3.29 10-10 3.87 12-8 4.40 14-5
2.62 8-7 3.44 11-3 4.11 13-6 4.68 15-4 2.62 8-7 3.44 11-3 4.11 13-6 4.68 15-4 2.49 8-2 3.27 10-9 3.91 12-10 4.46 14-7 2.25 7-5 2.96 9-8 3.54 11-7 4.03 13-2
3.29 10-10 4.33 14-2 5.24 17-2 5.93 19-5 3.29 10-10 4.33 14-2 5.24 17-2 5.93 19-5 3.14 10-4 4.12 13-6 4.99 16-4 5.65 18-6 2.83 9-4 3.72 12-3 4.51 14-9 5.10 16-9
2.99 9-10 3.93 12-11 4.98 16-4 5.64 18-6 2.99 9-10 3.93 12-11 4.98 16-4 5.64 18-6 2.85 9-4 3.75 12-4 4.75 15-7 5.37 17-7 2.57 8-5 3.38 11-1 4.29 14-1 4.85 15-11
2.62 8-7 3.44 11-3 4.31 14-2 5.00 16-5 2.62 8-7 3.44 11-3 4.39 14-5 5.25 17-3 2.49 8-2 3.27 10-9 4.18 13-9 5.06 16-7 2.25 7-5 2.96 9-8 3.76 12-4 4.36 14-4
3.29 10-10 4.33 14-2 5.37 17-8 6.24 20-6 3.29 10-10 4.33 14-2 5.53 18-2 6.54 21-6 3.14 10-4 4.12 13-6 5.27 17-3 6.23 20-5 2.83 9-4 3.72 12-3 4.69 15-4 5.44 17-10
2.99 9-10 3.81 12-6 4.65 15-3 5.40 17-9 2.99 9-10 3.93 12-11 4.88 16-0 5.66 18-7 2.85 9-4 3.75 12-4 4.79 15-8 5.81 19-1 2.57 8-5 3.32 10-11 4.06 13-4 4.71 15-5
2.55 8-5 3.11 10-2 3.80 12-6 4.41 14-6 2.62 8-7 3.26 10-8 3.99 13-1 4.63 15-2 2.49 8-2 3.27 10-9 4.13 13-7 4.79 15-9 2.23 7-4 2.71 8-11 3.31 10-10 3.84 12-7
Canada Mortgage and Housing Corporation
286
Notes to Table 21 1. Spans apply only where the floors serve residential areas. 2. Subfloor must comply with minimum requirements from Tables 18 and 19. 3. No bridging is assumed for spans for floor joists with concrete topping.
Commercial Designation Douglas fir – larch (includes Douglas fir and western larch)
Grade No. 1 and No. 2
Hem – fir (includes western hemlock and amabilis fir)
No. 1 and No. 2
Spruce, pine, or fir (includes spruce [all species except coast sitka spruce], jack pine, lodgepole pine, balsam fir and alpine fir)
No. 1 and No. 2
Northern species (includes any Canadian species covered by the NLGA Standard Grading Rules)
No. 1 and No. 2
Joist Size, mm in. 38 x 140 2x6 38 x 184 2x8 38 x 235 2 x 10 38 x 286 2 x 12 38 x 140 2x6 38 x 184 2x8 38 x 235 2 x 10 38 x 286 2 x 12 38 x 140 2x6 38 x 184 2x8 38 x 235 2 x 10 38 x 286 2 x 12 38 x 140 2x6 38 x 184 2x8 38 x 235 2 x 10 38 x 286 2 x 12
Maximum Span, m (ft.–in.) Joists with ceilings Joists with attached to Wood Furring concrete topping Joist Spacing, mm (in.) Joist Spacing, mm (in.) With or Without Without Bridging With Bridging Bridging3 300 400 600 300 400 600 300 400 600 12 16 24 12 16 24 12 16 24 3.29 10-10 4.06 13-4 4.78 15-8 5.44 17-10 3.29 10-10 4.06 13-4 4.78 15-8 5.44 17-10 3.14 10-4 3.87 12-8 4.55 14-11 5.18 17-0 2.83 9-4 3.50 11-6 4.11 13-6 4.68 15-4
2.99 9-10 3.83 12-7 4.50 14-9 5.12 16-10 2.99 9-10 3.83 12-7 4.50 14-9 5.12 16-10 2.85 9-4 3.64 11-11 4.28 14-1 4.88 16-0 2.57 8-5 3.29 10-10 3.87 12-8 4.40 14-5
2.62 8-7 3.44 11-3 4.11 13-6 4.68 15-4 2.62 8-7 3.44 11-3 4.11 13-6 4.68 15-4 2.49 8-2 3.27 10-9 3.91 12-10 4.46 14-7 2.25 7-5 2.96 9-8 3.54 11-7 4.03 13-2
3.29 10-10 4.33 14-2 5.24 17-2 5.93 19-5 3.29 10-10 4.33 14-2 5.24 17-2 5.93 19-5 3.14 10-4 4.12 13-6 4.99 16-4 5.65 18-6 2.83 9-4 3.72 12-3 4.51 14-9 5.10 16-9
2.99 9-10 3.93 12-11 4.98 16-4 5.64 18-6 2.99 9-10 3.93 12-11 4.98 16-4 5.64 18-6 2.85 9-4 3.75 12-4 4.75 15-7 5.37 17-7 2.57 8-5 3.38 11-1 4.29 14-1 4.85 15-11
2.62 8-7 3.44 11-3 4.31 14-2 5.00 16-5 2.62 8-7 3.44 11-3 4.39 14-5 5.25 17-3 2.49 8-2 3.27 10-9 4.18 13-9 5.06 16-7 2.25 7-5 2.96 9-8 3.76 12-4 4.36 14-4
3.29 10-10 4.33 14-2 5.37 17-8 6.24 20-6 3.29 10-10 4.33 14-2 5.53 18-2 6.54 21-6 3.14 10-4 4.12 13-6 5.27 17-3 6.23 20-5 2.83 9-4 3.72 12-3 4.69 15-4 5.44 17-10
2.99 9-10 3.81 12-6 4.65 15-3 5.40 17-9 2.99 9-10 3.93 12-11 4.88 16-0 5.66 18-7 2.85 9-4 3.75 12-4 4.79 15-8 5.81 19-1 2.57 8-5 3.32 10-11 4.06 13-4 4.71 15-5
2.55 8-5 3.11 10-2 3.80 12-6 4.41 14-6 2.62 8-7 3.26 10-8 3.99 13-1 4.63 15-2 2.49 8-2 3.27 10-9 4.13 13-7 4.79 15-9 2.23 7-4 2.71 8-11 3.31 10-10 3.84 12-7
Canada Mortgage and Housing Corporation
286
Notes to Table 21 1. Spans apply only where the floors serve residential areas. 2. Subfloor must comply with minimum requirements from Tables 18 and 19. 3. No bridging is assumed for spans for floor joists with concrete topping.
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