The Ontario Building Code | Hydraulic Loads on Branches
7.4.10.7. Hydraulic Loads on Branches
(1) No horizontal sanitary drainage pipe of less than 3 in. size shall have a fixture loading in excess of that permitted by Table 7.4.10.7.
Table 7.4.10.7.
Maximum Permitted Hydraulic Load Drained to a Branch
Forming Part of Sentence 7.4.10.7.(1)
| Item | Column 1 Size of Branch, in. | Column 2 Maximum Load, fixture units |
| 1. | 1 ¼ | 2 |
| 2. | 1 ½ | 4 |
| 3. | 2 | 6 |
In Plain Language
No horizontal sanitary drainage pipe smaller than 3 in. may carry a fixture load exceeding the specific limit set in this article, keeping smaller pipe from being overloaded.
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.