What is the minimum depth at which underground piping must be installed?

The minimum depth at which underground piping must be installed is set at 450 mm according to the National Plumbing Code of Canada. This depth is determined to safeguard the piping from potential surface loads and environmental conditions that could damage or compromise the integrity of the pipes.

Installing the piping at this depth also helps prevent freezing in colder climates, ensuring that the plumbing system operates effectively year-round. This regulation is critical for maintaining the longevity and reliability of plumbing installations, as well as for ensuring safety and functionality in residential and commercial applications.

The other depths listed do not align with the requirements specified in the code; therefore, they would not provide the same level of protection and compliance as the specified minimum of 450 mm.