A plumber is tasked with installing a new 150 mm building sewer crossing under a footing of a multi-storey commercial building. How should this penetration be installed to comply with the National Plumbing Code of Canada and ensure structural integrity?

Question: A plumber is tasked with installing a new 150 mm building sewer crossing under a footing of a multi-storey commercial building. How should this penetration be installed to comply with the National Plumbing Code of Canada and ensure structural integrity?

Answer options: ✅ The pipe should be sleeved with a larger diameter pipe extending at least 150 mm beyond the footing on both sides, with the annular space filled with a flexible sealant.

• The pipe can pass directly through the footing, provided it is well-supported on each side.
• A trench should be dug around the footing, and the pipe routed underneath without touching the footing.
• The pipe should be encased in concrete for at least 300 mm on either side of the footing for added strength.

Correct answer: The pipe should be sleeved with a larger diameter pipe extending at least 150 mm beyond the footing on both sides, with the annular space filled with a flexible sealant.

Explanation: According to the National Plumbing Code of Canada, pipes passing through or under structural elements like footings must be sleeved. The sleeve should extend a minimum distance (typically 150 mm) beyond the structural element on both sides, and the annular space filled with a flexible, waterproof material to allow for differential movement and prevent damage to the pipe or structure. Passing directly or encasing with rigid concrete can lead to pipe damage from settling or movement.