Customer is having issue with water leak coming into basement through main support beam of home. Previous plumbers in the past month have replaced water heater, PRV, flanges, toilet and stop valves. Cut ceiling in basement to further diagnose issue. Cut drywall around back to back bathrooms. Broke tile in standalone shower to chase down water leak. Went into attic to inspect flashing for ventilation line. Source of leak has not been found. Gave customer estimate for replacing both back to back shower valves that are both tiled in. Leak could be roof or gutter system recently installed.