The Ontario Building Code | Steel Beams
9.23.4.3. Steel Beams
(1) The spans for steel beams with laterally supported top flanges shall conform to Table 9.23.4.3. for floors and Tables A-20 to A-29 for roofs and floors.
Table 9.23.4.3.
Maximum Spans for Steel Beams supporting Floors in Dwelling Units
Forming Part of Sentence 9.23.4.3.(1)
| Item | Column 1 | Column 2 | Column 3 | Column 4 | Column 5 | Column 6 | Column 7 | Column 8 |
|
|
| supported Joist Length, m (Half the sum of joist spans on both sides of the beam) |
| |||||
|
|
| 2.4 | 3.0 | 3.6 | 4.2 | 4.8 | 5.4 | 6.0 |
|
| Section | One Storey supported |
|
|
|
|
| |
| 1. | W150 × 22 | 5.5 | 5.2 | 4.9 | 4.8 | 4.6 | 4.5 | 4.3 |
| 2. | W200 × 21 | 6.5 | 6.2 | 5.9 | 5.7 | 5.4 | 5.1 | 4.9 |
| 3. | W200 × 27 | 7.3 | 6.9 | 6.6 | 6.3 | 6.1 | 5.9 | 5.8 |
| 4. | W200 × 31 | 7.8 | 7.4 | 7.1 | 6.8 | 6.6 | 6.4 | 6.2 |
| 5. | W250 × 24 | 8.1 | 7.6 | 7.3 | 7.0 | 6.6 | 6.2 | 5.9 |
| 6. | W250 × 33 | 9.2 | 8.7 | 8.3 | 8.0 | 7.7 | 7.5 | 7.3 |
| 7. | W250 × 39 | 10.0 | 9.4 | 9.0 | 8.6 | 8.4 | 8.1 | 7.9 |
| 8. | W310 × 31 | 10.4 | 9.8 | 9.4 | 8.9 | 8.4 | 8.0 | 7.6 |
| 9. | W310 × 39 | 11.4 | 10.7 | 10.2 | 9.8 | 9.5 | 9.2 | 9.0 |
|
| Section | Two Storeys supported |
|
|
|
|
| |
| 10. | W150 × 22 | 4.9 | 4.4 | 4.1 | 3.8 | 3.5 | 3.4 | 3.2 |
| 11. | W200 × 21 | 5.6 | 5.1 | 4.6 | 4.3 | 4.1 | 3.8 | 3.7 |
| 12. | W200 × 27 | 6.4 | 6.1 | 5.6 | 5.3 | 4.9 | 4.7 | 4.4 |
| 13. | W200 × 31 | 6.9 | 6.5 | 6.2 | 5.8 | 5.4 | 5.1 | 4.9 |
| 14. | W250 × 24 | 6.8 | 6.1 | 5.6 | 5.2 | 4.9 | 4.6 | 4.4 |
| 15. | W250 × 33 | 8.2 | 7.7 | 7.0 | 6.5 | 6.1 | 5.8 | 5.5 |
| 16. | W250 × 39 | 8.8 | 8.3 | 7.8 | 7.2 | 6.8 | 6.4 | 6.1 |
| 17. | W310 × 31 | 8.7 | 7.8 | 7.2 | 6.7 | 6.2 | 5.9 | 5.6 |
| 18. | W310 × 39 | 10.0 | 9.3 | 8.5 | 7.9 | 7.4 | 7.0 | 6.7 |
(2) Beams described in Sentence (1) shall at least meet the requirements for Grade 350 W steel in CSA G40.21, "General Requirements for Rolled or Welded Structural Quality Steel".
(3) A beam may be considered to be laterally supported if,
(a) the wood joists bear on its top flange at intervals of 610 mm or less over its entire length,
(b) the load being applied to this beam is transmitted through the joists, and
(c) 19 mm by 38 mm wood strips in contact with the top flange are nailed on both sides of the beam to the bottom of the joist supported.
In Plain Language
Steel beams used within wood frame construction must meet the requirements set out in this article, covering their sizing and installation alongside wood members.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.