An elongated, flexible, flat conductive tape can be applied to any surface to be monitored for water or other liquid leaks, and electrically connected to any suitable type of conventional electrically operated
leak detector. A pair of parallel spaced conductors is disposed on one side of the tape that run longitudinally along the length thereof. The conductors are spaced from one another by a small distance to insure that only a small quantity of water or other conductive liquid is necessary to bridge the gap between the conductors, and create an electrical
short circuit or substantial impedance reduction between the two. In addition, the conductors are preferably as flat as possible to insure that liquid can freely flow transversely across them without being impeded thereby. Both of these features insure that the
detector tape can sense even very small quantities of liquid, thereby generating an early warning of a leak condition before extensive damage results. A liquid responsive visible indication is also provided on the tape to identify the location along the tape where water or other leaking liquid has come in contact therewith, and eliminates the need for using an expensive sensing device to locate the source of a leak.