The leak detection at the flat roof


Flat roofs need regular maintenance to detect and eliminate leaks. This affects both new and existing flat roofs alike, albeit to varying degrees. Depending on the roof construction, different methods of leak detection on the flat roof are available. The various techniques we will outline below.

The necessary maintenance of flat roofs is often neglected

In the 1970s, there was a veritable construction boom in flat roof constructions in Germany. The industry promoted with improved construction techniques and materials. For the most part, this is true, but was often neglected to inform the owner intensively about the need for regular roof inspections.

A flat roof must be inspected at least once a year by a competent and competent company. The supposedly safe water test is not recommended in many ways. On the one hand, so tons of valuable water are wasted. In addition, it is by no means guaranteed that the flat roof has no leaks.

The water can collect in the flat roof construction and may not drain away - for example, if a vapor barrier is installed. Accurate leak detection does not work in this way, as the water inside the roof structure can first make a path before it enters the masonry or the inside of the flat roof.

There are very accurate measuring methods for locating a leak

Over the past decades, different methods of detecting leaks on the flat roof have become established, with which a possible leak can not only be detected, but limited to a narrow range. Thus, the leak detection is the appropriate measure to detect and seal leaks even if they have not caused much damage.

  • Current pulse-measurement
  • Flue gas measurement
  • Trace gas measurement

Which method you should prefer to use for your flat roof for leak detection depends heavily on the flat roof construction.

  • warm roof
  • cold roof
  • inverted roof
  • duo roof

However, other properties of the flat roof also play an important role in the selection of the optimal positioning method.

  • Construction (roof type, as already mentioned)
  • construction
  • ballasted
  • Background of the leak detection (task)

The electro-impulse method

The electro-impulse method, for example, has proven itself for example in the warm roof flat roofs, which are preferably built in the 1970s. The seal is usually made of bitumen, this is possibly a gravel pile.

Particularly suitable for warm roofs

A loop is laid around the flat roof to be checked. For loads (gravel, greening), it is quite common that the loop remains in the surcharge or was taken into account in a model company during the construction period.

The stream always seeks its way down through the house mass. It flows on the principle of least resistance, which results in leaks. With the appropriate measuring instruments, the leak can be precisely defined.

Tracer gas and smoke gas measurement

If the roof now has a foil seal (for example EPDM rubber foil), the tracer gas process offers good measurement results. This procedure can be compared to a leak tester for split air conditioners.

Accurately locate leaks with sensors

From below, the flat roof is fumigated, while on the surface with the help of sensors, the gas leakage can be accurately detected. Similarly, the smoke-gas method works, in which also the path of the gas is detected. This method is well suited to skylights, penetrations, but also for very large flat roof systems, it is an efficient measurement option.

Tips & Tricks

The necessary equipment for the leak detection on the flat roof is very expensive. The purchase will not be amortized for most DIY enthusiasts. However, when looking for a suitable specialist company, make sure that all test procedures are really offered.

40 percent of the leak detection concern new flat roofs. The leak detection measurement methods used on older standing roofs account for around 60 percent.

You can already lay the laying of the loop for the later annual leak detection with the construction of the flat roof. Of course, we also provide you with contributions to [building a flat roof] in the house journal.


Video Board: Flat Roofing - 2 Ways to Find Leaks in Modified Bitumen Rolled Roofing