The Ontario Building Code | Support for Vertical Piping
7.3.4.4. support for Vertical Piping
(1) Except as provided in Sentence (2), vertical piping shall be supported at its base and at the floor level of alternate storeysby rests, each of which can bear the weight of pipe that is between it and the rest above it.
(2) The maximum spacing of supports shall be 7.5 m.