How a Family Home’s Basement Shower Kept Flooding Whenever Upstairs Drains Ran

https://direct-wiki.win/index.php/How_the_Martin_Family_Turned_a_Hidden_Sewer_Problem_into_a_Preemptive_Win

This is the story of a modest two-story house where the basement shower began backing up only when someone used a sink or shower on the main floor