I live in San Francisco, and my kitchen sink drain goes through my wall towards outside of the wall of the house into a light well. The steel pipes have rusted out so I want to replace them with ABS. Does any one know if this is legal or to code in SF? I have read that it is recommended to use a heavier duty pipe for more resistance to UV rays so maybe that would be “more” to code. Please advise!
I spoken with the San Francisco Building Code inspector and they said ABS exposed pipes are allowed as long as it is coated with UV protected paint since it’s located outdoors. Also ABS used for DWV applications are only allowed for buildings up to 2-stories private and commercial. For mixed material couplers, I would need to find a coupler made specifically for steel to plastic. Thanks @jim for telling me just to call the inspector.
For your climate PVC or ABS will work just fine since I’d doesn’t freeze however at least as of about 20 years ago San Francisco required all DWV pipe to be cast iron. San Francisco is a very liberal city with strong unions that lobbied for cast iron since it requires some skill to work with and beyond what most homeowners are willing to deal with giving union labor more work. This may have changed in the last 20 years though.