Leaks in the building envelope cause damage to the building and a loss of energy. Consequently, it is reasonable to localize critical weak points in both new and existing buildings to be able to implement the corresponding corrective measures. Building leak detection is the best method of localizing weak points so they can be eliminated.

Leakages can easily be visualized with a blower-door measuring device and fog or smoke. 

Leakages allow heat to escape from a room or cold air to flow in. Moreover, humidity can penetrate the building structure, which can lead to mold growth. Building leak detection visualizes leakages using generated fog, thermal images and/or leakage measurements. The following accessories are suitable for effective leak detection: 

  • Fog spray gun, fog machine, smoke pen
  • Thermal imaging camera
  • Anemometer
  • Ultrasonic leak detector

Performing building leak detection

When searching for leaks, a negative and/or positive pressure of approx. 50 Pascal is initially generated in the building with the aid of a blower fan. Then all structural components such as windows, shutter boxes, socket outlets and so on are checked for leaks using a fog spray gun, fog machine or a smoke pen. The smoke pen and the fog spray gun create a fine smoke that makes even minimal air movements visible. The fog allows the localization of any leaks. The position of the leaks can be quickly and simply marked with marking strips. This faciliates the documentation, for example with the aid of a digital camera. Possible leaks can be, for example, faulty, provisional seals as well as forgotten necessary seals.


  • Fog is used to visualize building leaks after a negative and/or positive pressure is generated in the building with the aid of a blower fan.
  • Possible leaks can be caused by faulty, provisional seals as well as by missing seals.
Leak detection with smoke stick at a socket