Method and apparatus to detect and locate roof leaks
First Claim
1. A method of locating a defect in a water impermeable membrane of a roof, where the roof comprises a generally horizontal roof support deck with the water impermeable membrane applied onto an upper surface of the support deck, the method comprising:
- locating a conductive detector on an upper surface of the roof membrane;
defining a shielding zone on the upper surface of the membrane by providing at least one shielding conductor on the upper surface and by generating an electrical potential difference between said at least one shielding conductor and the roof deck such that currents generated outside the zone are drawn to said at least one shielding conductor;
generating an electrical potential difference between the conductive detector and the roof deck such that, in the presence of a defect located within the zone, current flows between the roof deck and the conductive detector through moisture at the defect;
sensing the current between the roof deck and the conductive detector so as to detect any defect located within the zone;
and arranging the electrical potential difference between said at least one shielding conductor and the roof deck so as to be greater than the electrical potential difference between the conductive detector and the roof deck.
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Accused Products
Abstract
A leak in a membrane on top of a horizontal roof deck is located by applying conductive wires on the membrane underneath the aggregate in a grid pattern. A measuring and switching circuit generates voltage having a positive attached to the roof deck and a negative attached to the wires. The circuit has a relay for each wire which can be switched between a current sensor system and the negative potential. The sensor system is arranged to sense at each of the wires in turn the current flowing from the roof deck through any leak in the membrane to the wire. A micro-processor operates the relays in turn to connect all the other wires to the negative as a shield while each wire is sensed. From the output of the grid the changes in current in the x and y directions are analyzed to locate the leak in the membrane.
64 Citations
11 Claims
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1. A method of locating a defect in a water impermeable membrane of a roof, where the roof comprises a generally horizontal roof support deck with the water impermeable membrane applied onto an upper surface of the support deck, the method comprising:
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locating a conductive detector on an upper surface of the roof membrane; defining a shielding zone on the upper surface of the membrane by providing at least one shielding conductor on the upper surface and by generating an electrical potential difference between said at least one shielding conductor and the roof deck such that currents generated outside the zone are drawn to said at least one shielding conductor; generating an electrical potential difference between the conductive detector and the roof deck such that, in the presence of a defect located within the zone, current flows between the roof deck and the conductive detector through moisture at the defect; sensing the current between the roof deck and the conductive detector so as to detect any defect located within the zone; and arranging the electrical potential difference between said at least one shielding conductor and the roof deck so as to be greater than the electrical potential difference between the conductive detector and the roof deck. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification