07-03-2021, 01:51 AM
?We’ve had a hairline crack on our catchment tank for years ( since earthquakes in ‘18?). We were always going to patch it from inside (someday), but now I wonder: can I patch it from outside (with Flexseal or similar.)? It isn’t leaking much but moss is now growing so I’d like to clean it up without diving in. Has anyone done this? How effective might it be? Any and all speculation welcome…