The Ontario Building Code | Size and Spacing of Cleanouts
7.4.7.2. Size and Spacing of Cleanouts
(1) Except as provided in Sentences (2) and (3), on drainage piping of 4 in. size and smaller, the minimum size cleanout opening shall be the same size as the drainage pipe and on drainage piping larger than the 4 in. size, the cleanoutopening shall be 4 in. or larger and the maximum spacing between cleanouts on horizontal pipe shall be,
(a) in the case of a sink waste pipe, 6 m,
(b) in the case of a horizontal sanitary drainage pipe, or storm drainage pipe, other than a waste pipe from a sink, 15 m, and
(c) in the case of a horizontal sanitary drainage pipe or storm drainage pipe larger than 4 in. size, 30 m.
(2) The spacing between manholes serving a building sewer,
(a) 24 in. or less in size shall not exceed 90 m, and
(b) over 24 in. in size shall not exceed 150 m.
(3) The developed length of a building sewer between the buildingand the first manhole to which the building sewer connects shall not exceed 30 m.
(4) Cleanouts that allow rodding in one direction only shall be installed to permit rodding in the direction of flow.
(5) Manholes shall be located at all junctions and all changes in grade,size or alignment (except for curvilinear alignment) on a sanitary building sewer that is 8 in. or larger in size.
(6) Manholes shall be located at changes of grade, sizeor alignment (except for curvilinear alignment) on a storm building sewer or exterior storm drainage pipethat is 8 in. or larger in size.
In Plain Language
Except in specific cases, drainage piping of 4 in. size or larger needs cleanouts at specified size and spacing intervals, ensuring any part of a long drainage run can be reached for clearing a blockage.
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.