Windows play a central role in soundproofing. It is therefore very important also to consider the joint surrounding the window: if the materials selected are inappropriate or the components are not compatible with each other, the overall soundproofing will be compromised. The challenge: in contrast to large-area building components such as the windows themselves, sound-reduction index figures for joints are much more difficult to determine. On the one hand this is due to the diverse possibilities for filling the joints, and on the other hand the values determined in the laboratory are not necessarily directly applicable to the actual implementation.

The sealing experts at Hanno have taken on this challenge in order to be able to advise fabricators optimally using measured values and experience. "It was important for us to bring our soundproofing documentation up to the latest standards", said Dipl.-Ing. Björn Kethorn, Head of Application Engineering at Hanno. For this reason, working together with ift Rosenheim, comprehensive sound-reduction index figures for the Hanno portfolio were determined – for individual products as well as various system combinations. Added to this were real installation situations, in order to be able to present reliable values that are realistic in practice – with good results. Kethorn: "Our multifunctional tapes 'Hannoband-3E' and 'Hannoband-3E BG1' even achieved values of 58 dB in the tests, and with measurements that are true to practice – without any additional coating such as plaster or other sealants."

The findings from the test reports will now help Hanno to advise its customers more transparently and in a more targeted way. For one building in Munich it has even been possible to realize an individual detail solution. Together with the window manufacturer, the installation details were discussed and then successfully tested as a practical model by the Fraunhofer Institute. This way the requirements for the joints could be professionally realized when installing the 56 dB box-type windows. "Of course, such buildings are not the typical case. But they demonstrate what is possible using high-quality products in combination with good advice", Kethorn is pleased to say.