I inspected a 1990 DW Mobile today. Updated and renovated over the years and a very nice solid unit. My guess is the plumbing has also been updated. No PB supply lines which were common for the age. It’s common to see AAV’s used in mobiles along with “S” traps when there are limited DWV stacks.
There were 2 DWV’s roof penetrations. No attic access to observe them. All sinks had an AAV installed, somewhat. I didn’t get my pics in order, but the second one is a bathroom sink with a tie in wye. Could not determine where it went or terminated. No DWV roof stack located near that bathroom.
Thoughts? Not in violation of any local codes due to really not having any…
Left MB bathroom sink with AAV
Hall bathroom sink. Could not trace pipe going into side cabinet.
Right MB bathroom sink tying into left sink.