Thomas Runzheimer
Bibliographic info:
10th International BUILDAIR Symposium, March 31/ April 1, 2017, Hannover, Germany

Purpose of the work

Over the past years, the industry has launched a great number of products facilitating the airtight installation of sanitary fixtures in the airtight building envelope. However, the pre-wall mounting racks of cisterns remain a “key point” for assessing the airtightness of pre-walls.

Method of approach

As part of the rehabilitation of an indoor swimming pool, “airtight” pre-wall mounting racks were developed and used. This was due to the flush buttons causing “seepage” of the compound seal.

Content of the contribution

The presentation shows the relatively expensive, time-consuming, and repeated elimination of leakages in the areas of pre-walls in a new residential building. By contrast, it features the development and comparatively easy implementation of airtight cisterns as “single pieces”.

Results and the evaluation of their significance

Airtightness tests of new buildings as well as renovated buildings usually show air-inflow at the installation walls of the exterior walls. Around the toilet flush buttons, this cannot be simply remedied by further sealing. To eliminate the leakage the pre-wall must be completely removed. In contrast, the use of airtight cisterns would prevent leakages as we know it to work from airtight electrical installations.


Why do manufacturers not offer a solution here? After all, for all other frequently used installations airtight products are already available. Having said that, it might not be only a bad thing, because looking at the installation of the flush button you will see right away how much a construction team really knows about “airtightness”.


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