Hi everyone. I'm starting to plan out a kitchen remodel with a peninsula/island sink and have an interpretation question regarding a local plumbing ordinance (I will run everything by the inspector but want to make sure I'm not missing something obvious here). Here is what my local plumbing ordinance contains as an amendment to UPC 2009 (I've added comments where I see differences from the UPC language):
To me, this says:
So, I guess I have two questions. Is my reading accurate? If so, is there a function that the 5' run is providing to the system that the small loop vent from the thread I linked above does not provide?
Thanks in advance for any responses and for providing this resource online.
909.0 Special Venting for Island Fixtures.
Traps for island sinks and similar equipment shall be roughed in above the floor and may be vented by extending the vent as high as possible, and no lower than bottom of sink/fixture it serves [UPC 909.0 uses "drainboard height" here] and then returning it downward and connecting it to the horizontal sink drain more than five (5') feet (1524 mm) [UPC 909.0 uses "immediately"] downstream from the vertical fixture drain. The return vent shall be connected to the horizontal drain through a wye-branch fitting [UPC 909.0 also includes reference to a foot vent and connection with other vents >= 6" higher than flood level of fixtures served]. Drainage fittings shall be used on all parts of the vent and a minimum slope of one-quarter (¼") inch per foot (20.9 mm/m) back to the drain shall be maintained. [UPC 909.0 describes use of 45-90-45 for the loop construction here] Pipe sizing shall be as elsewhere required in this code with minimum size to be two (2") inch (51 mm) [UPC 909.0 has no reference to 2" minimum here]. The island sink drain, upstream of the return vent, shall serve no other fixtures. An accessible cleanout shall be installed in the vertical portion of the vent.
To me, this says:
- That the top of the loop should be as high as possible (up to the bottom of the countertop), but I don't have to build a two-level island to be able to accommodate the "above drainboard height" requirement (I assume drainboard means counter top, but don't see a definition anywhere)
- As long as I run at least 5' horizontally and use 2" PVC, I can connect the "vent" side to the drain side and do not need to tie the "vent" side into an existing vent, run a new vent to the outside or use an AAV
So, I guess I have two questions. Is my reading accurate? If so, is there a function that the 5' run is providing to the system that the small loop vent from the thread I linked above does not provide?
Thanks in advance for any responses and for providing this resource online.