Tempo:
Table 20 Maximum spans for floor joists – general cases1, 2 Maximum Span, m (ft.–in.) Joist Spacing, mm (in.)
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.
300 12
400 16
600 24
300 12
400 16
600 24
With Strapping and Bridging 300 400 600 12 16 24
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
3.09 10–2 3.71 12–2 4.38 14–4 4.99 16–5 3.09 10-2 3.71 12–2 4.38 14–4 4.99 16–5 2.92 9–7 3.54 11–7 4.17 13–8 4.75 15–7 2.51 8–3 3.19 10–6 3.76 12–4 4.29 14–1
2.91 9–7 3.53 11–7 4.16 13–8 4.75 15–7 2.91 9–7 3.53 11–7 4.16 13–8 4.75 15–7 2.71 8–11 3.36 11–0 3.96 13–0 4.52 14–10 2.33 7–8 3.04 10–0 3.58 11–9 4.08 13–5
2.62 8–7 3.36 11–0 3.96 13–0 4.52 14–10 2.62 8–7 3.36 11–0 3.96 13–0 4.52 14–10 2.49 8–2 3.20 10–6 3.77 12–4 4.30 14–1 2.16 7–1 2.84 9–4 3.41 11–2 3.88 12–9
3.29 10–10 4.00 13–1 4.66 15–3 5.26 17–2 3.29 10–10 4.00 13–1 4.66 15–3 5.26 17–2 3.14 10–4 3.81 12–5 4.44 14–6 5.01 16–4 2.83 9–3 3.44 11–3 4.01 13–1 4.53 14–9
2.99 9–10 3.76 12–4 4.38 14–4 4.94 16–2 2.99 9–10 3.76 12–4 4.38 14–4 4.94 16–2 2.85 9–4 3.58 11–9 4.17 13–8 4.71 15–5 2.57 8–5 3.23 10–7 3.77 12–4 4.25 13–11
2.62 8–7 3.44 11–3 4.11 13–6 4.65 15–3 2.62 8–7 3.44 11–3 4.11 13–6 4.65 15–3 2.49 8–2 3.27 10–9 3.92 12–10 4.42 14–6 2.25 7–5 2.96 9–8 3.54 11–7 4.00 13–1
3.29 10–10 4.19 13–9 4.84 15–10 5.43 17–10 3.29 10–10 4.19 13–9 4.84 15–10 5.43 17–10 3.14 10–4 3.99 13–1 4.60 15–1 5.17 17–0 2.83 9–4 3.60 11–10 4.16 13–8 4.67 15–4
With Strapping
With Bridging
2.99 9–10 3.90 12–10 4.51 14–10 5.06 16–7 2.99 9–10 3.90 12–10 4.51 14–10 5.06 16–7 2.85 9–4 3.72 12–2 4.29 14–1 4.82 15–10 2.57 8–5 3.36 11–0 3.88 12–9 4.35 14–4
2.62 8–7 3.44 11–3 4.20 13–10 4.72 15–6 2.62 8–7 3.44 11–3 4.20 13–10 4.72 15–6 2.49 8–2 3.27 10–9 4.00 13–2 4.49 14–9 2.25 7–5 2.96 9–8 3.62 11–10 4.06 13–4
Canada Mortgage and Housing Corporation
285
Note to Table 20 1. Spans apply only where the floors serve residential areas. 2. Subfloor must comply with minimum requirements from Tables 18 and 19.
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.
300 12
400 16
600 24
300 12
400 16
600 24
With Strapping and Bridging 300 400 600 12 16 24
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
3.09 10–2 3.71 12–2 4.38 14–4 4.99 16–5 3.09 10-2 3.71 12–2 4.38 14–4 4.99 16–5 2.92 9–7 3.54 11–7 4.17 13–8 4.75 15–7 2.51 8–3 3.19 10–6 3.76 12–4 4.29 14–1
2.91 9–7 3.53 11–7 4.16 13–8 4.75 15–7 2.91 9–7 3.53 11–7 4.16 13–8 4.75 15–7 2.71 8–11 3.36 11–0 3.96 13–0 4.52 14–10 2.33 7–8 3.04 10–0 3.58 11–9 4.08 13–5
2.62 8–7 3.36 11–0 3.96 13–0 4.52 14–10 2.62 8–7 3.36 11–0 3.96 13–0 4.52 14–10 2.49 8–2 3.20 10–6 3.77 12–4 4.30 14–1 2.16 7–1 2.84 9–4 3.41 11–2 3.88 12–9
3.29 10–10 4.00 13–1 4.66 15–3 5.26 17–2 3.29 10–10 4.00 13–1 4.66 15–3 5.26 17–2 3.14 10–4 3.81 12–5 4.44 14–6 5.01 16–4 2.83 9–3 3.44 11–3 4.01 13–1 4.53 14–9
2.99 9–10 3.76 12–4 4.38 14–4 4.94 16–2 2.99 9–10 3.76 12–4 4.38 14–4 4.94 16–2 2.85 9–4 3.58 11–9 4.17 13–8 4.71 15–5 2.57 8–5 3.23 10–7 3.77 12–4 4.25 13–11
2.62 8–7 3.44 11–3 4.11 13–6 4.65 15–3 2.62 8–7 3.44 11–3 4.11 13–6 4.65 15–3 2.49 8–2 3.27 10–9 3.92 12–10 4.42 14–6 2.25 7–5 2.96 9–8 3.54 11–7 4.00 13–1
3.29 10–10 4.19 13–9 4.84 15–10 5.43 17–10 3.29 10–10 4.19 13–9 4.84 15–10 5.43 17–10 3.14 10–4 3.99 13–1 4.60 15–1 5.17 17–0 2.83 9–4 3.60 11–10 4.16 13–8 4.67 15–4
With Strapping
With Bridging
2.99 9–10 3.90 12–10 4.51 14–10 5.06 16–7 2.99 9–10 3.90 12–10 4.51 14–10 5.06 16–7 2.85 9–4 3.72 12–2 4.29 14–1 4.82 15–10 2.57 8–5 3.36 11–0 3.88 12–9 4.35 14–4
2.62 8–7 3.44 11–3 4.20 13–10 4.72 15–6 2.62 8–7 3.44 11–3 4.20 13–10 4.72 15–6 2.49 8–2 3.27 10–9 4.00 13–2 4.49 14–9 2.25 7–5 2.96 9–8 3.62 11–10 4.06 13–4
Canada Mortgage and Housing Corporation
285
Note to Table 20 1. Spans apply only where the floors serve residential areas. 2. Subfloor must comply with minimum requirements from Tables 18 and 19.
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