Is residential house built in 1988 required to have a clean out for sewer main line?
The first floor bathroom frequently got backup in my property in Oak Park California. The house is built around 1988-89. The plumbers came claiming they could not find a clean out for the sewer main line. Is the installed above ground near the house an aluminum cone shape cover in the attached photo served as a vent as well as a clean out for the main line sewer?
