The Ontario Building Code | Thrust Restraint of Water Service Pipes
7.3.4.9. Thrust Restraint of water service Pipes
(1) pipe clamps and tie-rods, thrust blocks, locked mechanical or push-on joints, mechanical joints utilizing set screw retainer glands, or other suitable means of thrust restraint shall be provided at each change of direction of a water service pipe 4 in. or more in size and at all tees, plugs, caps and bends.
(2) Backing for underground water service pipesshall be placed,
(a) between undisturbed earth and the fitting to be restrained and shall be of sufficient bearing area to provide adequate resistance to the thrust to be encountered, and
(b) so that the joints will be accessible for inspection and repair.
(3) Concrete thrust blocks shall have a minimum compressive strength of not less than 10 MPa after 28 days.
(4) Thrust blocks shall not be used to restrain vertical pipe.
7.3.5. Protection of Piping
In Plain Language
Where a water service pipe changes direction, pipe clamps and tie-rods or another means of thrust restraint are needed, since water pressure pushing through a bend, tee, or elbow can otherwise force the joint apart.
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.