The “shower pan†under our ground floor shower has developed a leak. Instead of a digging up the tile and replacing the “Shower Panâ€, are thinking of having a “Prefabricated Shower Stall†installed. Needless to say this would not be worth it if water would still seep into the leaking “shower pan†afterwards –is there a 100% SURE way to do such an installation without digging up the tile and replacing the “shower pan†BEFORE installing the “prefabricated shower stall†or do we really need to do both?