Monitoring of water­pro­ofing and struc­tural moisture protection: The limits of point measu­rement methods and the need for innovative approaches

The punctual measu­rement of physical quantities is undoub­tedly considered a proven method for charac­te­rizing the behavior of components, especially if the material behavior can be assumed to be homoge­neous and isotropic. It enables precise recording of specific parameters and provides valuable insights into the behavior of building struc­tures. However, selective measu­rement methods often reach their limits where unfore­seeable, disruptive events, the location of which cannot be predicted in advance, must be quickly detected and localized in order to avoid conse­quential damage.

This is mainly due to the fact that monitoring methods based on discrete, distri­buted measuring points are often not repre­sen­tative of the entire monitoring area due to the low density of measuring points. Especially in the case of events such as leaks, cracks or other unexpected damage, the occur­rence of which cannot be clearly predicted, punctual measu­re­ments can have diffi­culty locating them in time and accurately.

To meet this challenge, a paradigm shift towards conti­nuous, area-based monitoring is proving to be promising. ProGeo has recognized this and has been developing techno­logies for more than 30 years that econo­mically enable compre­hensive monitoring of even very large objects. These approaches allow the relevant parameters to be conti­nuously recorded across the entire area to be monitored. This not only overcomes the weaknesses of point measu­re­ments, but also detects disruptive events immediately and precisely, regardless of where they occur.

The following practical examples illus­trate the effec­ti­veness of this approach:

Monitoring of buried plastic seals

The metro­lo­gical monitoring of buried water­pro­ofing in the environ­mental protection sector is made possible by the BAM-approved geologger® seal control system. This system is based on an areal recording of the electrical resis­tance distri­bution of the monitored sealing. It uses a voltage diffe­rence imprinted in the electri­cally conductive soil layers adjacent to the water­pro­ofing and records the potential distri­bution that occurs with a grid of measuring points in one of the soil layers.

Thanks to a measuring grid of 5 to 10 metres, which is usually used in practice, the smallest leaks can be located with an accuracy of a few decimetres, regardless of where they occur. This process is now state-of-the-art and is mandatory for certain landfill classes and facilities for handling water-polluting substances.

Real-time monitoring of building water­pro­ofing

The metro­lo­gical monitoring of green and used flat roofs is imple­mented by means of the real-time monitoring system smartex mx®, which enables conti­nuous recording of the entire roof area. This system works according to the same measuring principle as the geologger® system, whereby the voltage diffe­rence between the wet cover or wear layers is applied to the water­pro­ofing and an electri­cally conductive contact layer located below the water­pro­ofing.

Changes in the potential distri­bution in the contact position as a result of leaks that occur are measured automa­ti­cally and conti­nuously with a matrix of sensor points. This enables immediate detection and precise location of the leak, regardless of the location of the leak in the

Sealing. In addition, the system also provides quali­tative location-specific infor­mation about the moisture distri­bution within warm roof struc­tures.

smartex® mx is available in various design variants and is suitable for use with loosely laid, mecha­ni­cally fastened and fully hot-glued or self-bonded seals.