The Ontario Building Code | Spans for Joists, Rafters and Beams
188.8.131.52. Spans for joists, Rafters and Beams
(1) Except as required in Sentence (2) and Article 184.108.40.206., 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.
(2) Spans for floor joists that are not selected from Tables A-1 and A-2 and that are required to be designed for the same loading conditions, shall not exceed the design requirements for uniform loading and vibration criteria.
(4) Spans for roof ridge beams shall conform to the spans in Table A-12 for the uniform snow load shown.