Code Tech Logo

Question: 08-22 Code Section: 7 Date: 7 May 2008 OBC 2006 Reference:;

Question: (There is) a concern over what is a building drain and how should it be installed.

Interpretation: A sanitary building drain means a building drain that conducts sewage to a building sewer from the most upstream soil or waste stack, branch or fixture drain serving a water closet. The building drain is the lowest horizontal piping, including any vertical offset, that conducts sewage, clear water waste or storm water by gravity to a building sewer. and (3) states that a sanitary building drain (minimum of 4 inch) is terminated at a 3 inch soil stack or a 3 inch waste stack or a 3 inch vent stack. states that where a building drain enters the building above floor level, the building drain may be deemed to terminate at the first horizontal to vertical change of direction. A building drain must terminate at its most upstream end to the farthest SOIL STACK serving a water closet. This soil stack must extend a minimum of 3" to open air. If the stack is at the front of the building and a kitchen sink is at the back of the building then the building drain ends at the soil stack at the front of the building.

Approved at AMES 2008


Copyright 2016 Ontario Plumbing Inspectors Association, Inc.