Customer called in about leak coming from ceiling. Tenant said that leak was not constant and only appeared randomly. Went through and tested fixtures in bathroom above where leak was. Load tested sink. Flushed toilet 3 times. Ran water in tub. Removed trim for waste and overflow. Waste and overflow was not seated correctly. It appeared that silicone was placed around waste and overflow gap but had now failed. Poured water into waste and overflow and the leak presented itself in apartment below. Cut open drywall to expose piping. Note: management was notified that drywall repair would have to be done by others. Removed existing waste and overflow. Installed new waste and overflow along with new piping. Load tested tub 5 times. Ran water at tub for 10 minutes. No sign of leaks At this time. Thank you for choosing CPI plumbing and heating!