Early aging - a challenge for subroof films

Under-roof films play a leading role in roof construction. Only if they provide long-term functionality can the roof be optimally protected from the weather. Ideally, the membrane, along with tiles and rafters, should last the entire life of the roof. In recent years, however, roofers are increasingly reporting roofs where under-roof membranes are failing after only a few years, even though they have passed aging procedures according to applicable standards. How is this possible?

DELTA innovation for the roofs of tomorrow

The engineers at Dörken have now made a breakthrough. They discovered that the biggest and until now completely underestimated factor lies beneath the roofing membrane: the air movement at the level of the tenon slats. This damaging influence, which at first glance seems minimal, stresses the membrane over the years. Ultimately, it leads to premature aging and limits the functioning of the roof. Using a combination of specially adapted materials and the use of innovative technology, the team of engineers succeeded in significantly slowing down the aging process of under-roof foils. For Dörken, this was the beginning of Mission XX - The discovery of longevity.

Engineering and expertise of DELTA

To demonstrate the effectiveness of this innovation, a suitable test procedure is particularly important. Since there was no test procedure that took air movement into account to the extent required, Dörken developed the so-called "storm oven test." This is now also offered by an independent testing institute and is a permanent part of the European Assessment Document (EAD) for under-roof films. The test includes a unique thermo-oxidation procedure in which the membranes are exposed not only to high temperatures, but also to permanent strong air movement - over a period of 64 weeks. This test simulates several decades of roof use, whereas the current standard aging procedure provides assurance for a period of only three years. Under-roof foils that are not sufficiently resistant to aging can now be recognized by subjecting them to an artificial aging process using the "storm furnace test." This new procedure will provide a high degree of certainty to all manufacturers and users in the future. This groundbreaking development will set a new standard for under-roof films - made for roofs that last.