The Ontario Building Code | Grade Marking
9.3.2.1. Grade Marking
(1) Lumber for joists, rafters, trusses and beams and for the uses listed in Table 9.3.2.1. shall be identified by a grade stamp to indicate its grade as determined by the NLGA, "Standard Grading Rules for Canadian Lumber".
Table 9.3.2.1.
Minimum Lumber Grades for Specific End Uses
Forming Part of Sentences 9.3.2.1.(1) and 9.3.2.2.(1)
| Item | Column 1 | Column 2 | Column 3 | Column 4 | Column 5 |
|
| Use | Boards |
|
| Framing |
|
|
| Paragraph in the NLGA Grading Rules Under Which Boards are Graded |
| ||
|
|
| All Species |
| Eastern White Pine & Red Pine | All Species |
|
|
| Para 113 | Para 114 | Para 118 |
|
| 1. | stud wall framing (loadbearing members) | — | — | — | stud, Standard, No. 2 |
| 2. | stud wall framing (non-loadbearing members) | — | — | — | stud, Utility, No. 3 |
| 3. | Plank frame construction (loadbearing members) | No. 3 Common | — | No. 3 Common | No. 2 |
| 4. | Plank frame construction (non-loadbearing members) | No. 5 Common | — | No. 5 Common | Economy, No. 3 |
| 5. | Post and beams less than 114 mm in thickness | — | — | — | Standard, No.2 |
| 6. | Post and beams not less than 114 mm in thickness | — | — | — | Standard |
| 7. | Roof sheathing | No. 3 Common | Standard | No. 4 Common | — |
| 8. | Subflooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring | No. 3 common | Standard | No. 3 Common | — |
| 9. | wall sheathing when required as a nailing base | No. 4 Common | Utility | No. 4 Common | — |
| 10. | wall sheathing not required as a nailing base | No. 5 Common | Economy | No. 5 Common | — |
In Plain Language
Lumber must be grade marked as set out in this article, so its structural grade and quality can be verified at the building site.
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.