The VILPE Sense leak detector found a leak on the factory roof and helped to limit roof renovation costs by 45,000 euros

Five years ago, Timo Anttila, technical director of VILPE Oy, noted that there was most likely a leak on the roof of VILPE’s factory in Korsholm, in Finland. Occasionally, water penetrated the roof from several spots, indicating that the wool insulation was wet. The factory’s roof covers a total area of 16,500 m². Since the area of the suspected leak was about 1,000 m², Anttila knew that finding the potential leak on such a large roof would not be easy.

“Visually detectable leaks are rare, and this leak was no exception. We had no idea where to start looking,” Anttila describes the challenges of locating the leak.

Finding a leak is also complicated by the fact that leaks are often not found at the spot where the water enters the building. For instance, in VILPE’s case, the roof structure consists of TT-plates topped with a vapor barrier, wool insulation, and a felt cover. Once the water has penetrated through the insulation, it flows along the sloping structural roof until it finds a place to leak through.

The VILPE Sense leak detector narrowed down the damaged roof area

The large roof was not immediately opened and repaired. VILPE was developing products intended to address leakages, and the potential leak was seen as an opportunity for product testing. Ten VILPE Sense leak detectors were installed at approximately four-meter apart in the suspected leak area. Later, four more were added. The VILPE Sense leak detector continuously monitors the roof’s humidity levels, alerts to excessive humidity, and helps to locate the leak on the roof. By limiting the leak to a smaller area, it is also possible to limit the area of the renovation work.

The repair costs for the leak were 15,000 euros

The VILPE Sense system immediately confirmed Anttila’s suspicion of a roof leak. The extent of the damage was limited to a 125 m² area of the roof, which was opened and inspected. Without the VILPE Sense system, a 1,000 m² area of the roof would have needed to be opened and replaced, which would have incurred total costs of about 60,000 euros. During the renovation, the wool insulation, felt, and vapor barrier were replaced in an area of 115 m². Three Alipai underpressure vents were also installed on the roof area. The total cost of the renovation was 15,000 euros, meaning that the VILPE Sense leak detectors helped save 45,000 euros.

The cause of the leak or its exact location was never discovered. However, Anttila estimated that if the VILPE Sense leak detectors had been installed from the beginning, the leak would have been detected immediately upon its occurrence, and the repair would have been easy. According to Anttila, repairing a small leak at an early stage would have cost between 1,000 and 2,000 euros.

Information about the building

  • VILPE’s factory in Korsholm, Finland
  • The factory was originally built in 1982 but has been expanded several times. The section of the roof where the leak was found was constructed in 1990 and renovated in 2010
  • Roof size and material: Low-pitch roof with felt as the roofing material. Beneath this, there is wool insulation, a vapor barrier, and TT-plates. The total roof area is 16,500 m²
  • VILPE Sense products: 14 VILPE Sense leak detectors
  • Roof renovation: Replacement of felt, wool insulation, and vapor barrier in an area of 115 m². Installation of three Alipai underpressure vents
  • Cost of roof renovation: 15,000 euros. Estimated repair costs if VILPE Sense leak detectors had been installed before the leak: 1,000–2,000 euros. Estimated repair costs without the VILPE Sense system: 60,000 euros