Zoned roof monitoring system

A method of detecting a leak in a roof, wherein the roof comprises a generally horizontal roof support deck with a water impermeable membrane applied on top of the roof support deck, the method comprising:

• dividing the membrane into a plurality of separate zones;
• in each zone applying at or adjacent the membrane a sensor device arranged to detect moisture underneath the membrane;
• providing a movable scanning device having a power supply antenna for supplying power by an electromagnetic wave to the sensor device;
• moving the scanning device to selected ones of the zones;
• wherein in each respective zone, at least one length of a moisture sensor detection tape arranged to detect moisture underneath the membrane is applied at or adjacent the membrane;
• where said at least one length of the moisture detection tape has conductors arranged so that a resistance between the conductors is proportional to moisture in the respective zone;
• wherein in each zone the sensor device includes measurement and signaling electronics to take resistance readings from said at least one length of the moisture detection tape which are proportional to moisture in the respective zone;
• at each selected zone causing the power supply antenna to supply power to the sensor device in the respective zone;
• using the power supplied, causing the sensor device to emit signals related to the moisture underneath the membrane as detected by the sensor device;
• and detecting the signals at the mobile scanning device.