Shower stall against an outside wall is leaking water outside between the foundation and the brick. Had numerous small cracks in fiberglass shower stall resurfaced so that is no longer the problem and snaked a hose into the drain. No leakage from inside the pipe, but it continues to leak. Plumber caulked around the drain, but it continues to leak. Tried epoxy and it still leaks. Any other products available? Any suggestions?