Abstract: A method and apparatus for differential voltage grid-based moisture monitoring of structures is provided. The method involves detecting a defect in a structural component, the structural component comprising a membrane for fluid impermeability, a deck for supporting the membrane, and a plurality of electrically conductive elements adjacent the membrane and electrically insulated from each other, by sensing the potential difference between a first element of the plurality of elements and a second element of the plurality of elements separated from the first element when there is an electrical potential between the deck and an electrically conductive fluid in contact with the first and second elements. The apparatus includes a switching circuit for connecting a voltage measuring circuit to the first and second elements, the voltage measuring circuit being operable to sense the potential difference between the first and second elements.

Abstract: A moisture detection sensor is used in a building structure to detect moisture penetration. The sensor is a flat adhesive tape of a substrate of dielectric, hydrophobic material. Three or four elongate, parallel, conductors are secured to the top surface and a protective layer of non-hygroscopic, water pervious material is secured over two of the conductors so that they are exposed to surface moisture. One or two of the conductors are covered by an insulating layer to prevent moisture access. Pairs of moisture probes along the length of the tape penetrate the insulating layer, the respective conductors and the substrate and to extend into a building component to which the substrate has been adhered. A diode guide arrangement allows a monitoring unit to monitor the exposed conductors for surface moisture and the penetrated conductors for moisture in the component by reversing polarity of the voltage across the conductors.

Abstract: A moisture detection sensor is used in a building structure to detect moisture penetration. The sensor is a flat adhesive tape of a substrate of dielectric, hydrophobic material. Three or four elongate, parallel, conductors are secured to the top surface and a protective layer of non-hygroscopic, water pervious material is secured over two of the conductors so that they are exposed to surface moisture. One or two of the conductors are covered by an insulating layer to prevent moisture access. Pairs of moisture probes along the length of the tape penetrate the insulating layer, the respective conductors and the substrate and to extend into a building component to which the substrate has been adhered. A diode guide arrangement allows a monitoring unit to monitor the exposed conductors for surface moisture and the penetrated conductors for moisture in the component by reversing polarity of the voltage across the conductors.