Have direct overflow so don't need auto -stop,thanks for suggestion though. Of the two floods the first one the Ro'S main feed came off and the second one the tank cracked. Thanks RobPs really need to contain units potential flood issue from main house.
I didnt think building regs permitted attached garges having same floor level as house, fire hazzard and all that.
Thanks for replies,shall put timber skirt and silicone to contain any flood. This is my Garage.