Appeal 7057

Uniform Plumbing Code 905.3

UPC Section 905.3: Unless prohibited by structural conditions, each vent shall rise vertically to a point not less than six (6) inches above the flood-level rim of the fixture served before offsetting horizontally.

The proposed design includes flat venting of back-to-back tubs and water closets. This flat venting includes coming off of the waste pipe at a 45 degree angle above the flow line and running parallel to the waste pipe back to the chase. The vent line would rise above the flood rim of the fixtures before tying together. A wall cleanout would be provided on the vent line for each water closet where this flat venting occurs. The vents wall cleanout will be located within each individual unit above the water closet tank. The rooms/housing units with flat venting of water closets and tubs are as follows:505, 507, 511, 512, 513, 515, 525, 527, 529 and 530. See attached typical partial plan and typical partial riser diagram of these affected areas.

Reduced ceiling heights at bottom of plumbing stacks at the fourth floor serving 10 housing units results in an alternate means of venting the tubs and water closets. These fixtures were flat vented to eliminate a figure five fitting (typically installed throughout building) which would have pushed the ceiling down to below 7 foot at this floor only.

This flat venting of these types of fixtures is normally acceptable and installed on projects in the east coast without posing any design/installation problems. This method has also been accepted on a past local project (done by our office) without an appeal or variance from the local authority.