08-06 Wet vent using back vent

Question: 08-06Code Section: 7Date: 8 February 2008OBC 2006 Reference:,

Question: The attached illustration… (is)…in regards to the venting of a water closet and bath tub installation. Our inspectors are seeing this in housing and to me it does not look right but I am wondering if it meets the wet venting requirements as written in the code. I have read over and cannot seem to find any wording that can restrict this type of installation.

Interpretation: Section refers to the “continuous vent” serving a wet vent. The diagram shows a “back vent”. The definition in section defines it as an extension of a VERTICAL section of a branch or fixture drain. Note all the explanatory drawings in the appendix all show the wet vent terminating in a continuous vent that we used to call a continuous waste and vent.

Approved at AMES 2008