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Research Project



Water and moisture –

a constant threat for flat roofs


The requirements for roofs have changed. Nowadays, flat roofs are no longer merely coverings for the building envelope, they have become extended useable spaces and living spaces regardless of whether they have been planted with greenery or equipped with solar power plants. Roofs are no longer a simple covering but rather an integrative part of modern building design concepts. They must have a guaranteed long service life and work without problems.

Water and moisture affect the roof's lifetime! Water penetration due to poor workmanship or leaks in the roof membrane as well as an invisible increase in moisture in the roof present a risk for the supporting structure and in most cases this leads to very high renovation costs.

The solution to permanent moisture monitoring is: Roof Protector, a completely new measuring technology for permanently monitoring the moisture in flat roofs. The product can be installed during the construction phase and can also be retrofitted.



Research Project „Roof Protector“


A research project to develop an indicator for detecting moisture in low-pitched non-ventilated roofs was launched in 2010 on the initiative of a roofing company with special expertise in flat roofs which operates throughout Austria.

The research project was carried out in collaboration with partners from industry, science and trade, including Carinthia Technical College, the Institute for Flat Roof Construction and Structural Waterproofing, and Carinthian Tech Research and will be completed at the end of 2015.



Expert opinions on the Roof Protector:


Dr. Christoph Buxbaum, Dipl. Ing.; generally sworn and legally certified expert:

The Roof Protector enables verification of the fitness for purpose and building physics principle of warm roofs (non-ventilated, insulated flat roof structures in accordance with Austrian Standard B 3691:2012) and can therefore be used as an effective tool for increasing the lifetime of modern flat roof structures.



Wolfgang Hubner IFB-Institut für Flachdachbau und Bauwerksabdichtung:

"Expedient renovation can only be carried out if the structural behaviour of components is known. The upstream use of Roof Protectors for component analysis can be recommended for every upcoming renovation."




The development partners at a glance 

1.1. Objective for the research project


Development of a completely novel measuring technology – a system which is built into the roof structure and has measuring sensors that transmit the data to a central control room by means of a radio sensor. The system should identify the following damage at an early stage:

    • Tears in the sealing membrane
    • Material ageing, brittleness, blistering
    • Breaks in the sealing membranes at joining points
    • Damage due to the wrong combination of materials
    • Stress cracks caused by inadequate expansion joints
    • Thermal bridges due to material shrinkage


      1.2. Development targets


      • Develop a sensor technology for reliable detection of moisture
      • Develop a mounting for holding the sensors and for installing in the building envelope
      • Evaluate threshold values for interpretation
      • Laboratory tests to verify the statements
      • Build up necessary building physics expertise


      An open air test rig with more than 150 measuring sensors was set up to support the development. Parallel to this, several pilot construction sites were set up with different roof structures and were constantly measured. The objective was to generate a comprehensive database as a basis for the assessment. Now after more than 4 years of development, a product concept has emerged where statements can be made about the standard behaviour of different roof structures and any deviations from the standard can be highlighted specifically.

      Product development including the field test phase is complete and, from the results of the development, the innovative "Roof Protector" product can be used for the following areas:


      • Moisture detection in low-pitched non-ventilated roof constructions
      • Demonstration of leak-tightness and the roof's functional condition
      • Demonstration of moisture development in the roof system
      • Demonstration of successful roof renovation
      • Demonstration of correct maintenance
      • Preservation of evidence in the event of damage
      • Demonstration of drying out or humidification of the roof system
      • Determination of moisture which adversely affects the substance


      In summary it can be said, if the product is used correctly and the data obtained are expertly interpreted, that the result is a professional status assessment of the roof system and this leads to safer use of the roof area beyond its theoretical service life.


      1.3. Principle of operation


      The metrological study is based on electrical conductivity, the conductance being measured between two electrodes (applied in a prefabricated, cylindrical component) introduced into the roof structure. A small measured value is achieved with higher levels of moisture, whereas a high measured value is achieved in the dry state. The measured values range between 0 and 100 units, whereby very differentiated documentation can be obtained for humidification or drying out. The data generated can be either recorded in handwriting by means of individual measurements or sent via wireless sensors to a central data control room.



      1.4. Results and findings from the project


      In general, it is an admissible conclusion that most flat roof structures contain moisture, the change in which must be observed in each case to ensure an ultimately optimal service life for the flat roof system in line with requirements.

      All academic studies have shown that the different seasons, conditions of use and any superstructures are to be considered on a case by case basis. This leads to the important realisation that all parameters and influencing variables can be usefully measured and compared to permit a valid assessment.

      Now, after 4 years of development and test construction sites and initial pilot projects that have successfully completed the tests, it has been decided that a startup company will offer the new product on the market under the "Roof Protector" brand.