Thomas Runzheimer
Bibliographic info:
11th International BUILDAIR Symposium, 24- 25 May 2019, Hannover, Germany

Purpose of the work

The load-bearing structures of historical wooden buildings have a large number of joints and penetrations that are difficult to seal. For reasons of preservation of historical monuments, wooden buildings often have to be sealed at the interior of the load-bearing structure. The existing substrates in these areas are not well suited for proper execution and, as a complicating factor, the load-bearing structures or parts of these should often remain visible.

Method of approach

Airtightness measurements in practice rarely show good results at the eaves-side connection of roof structures to wooden beam ceilings, especially if the ceilings here are not fully exposed.

Even if the connections are readily accessible, the existing substrates usually require special techniques to create an airtight layer.

Content of the contribution

Special solutions to create a high-quality air seal were developed during fitting out of an attic for a particular historical building. In addition to the basic planning, details of the practical implementation are also presented.

Results and the evaluation of their significance

Airtightness measurements during the construction work showed excellent results at the joints and penetrations of the sealing layer to the visible supporting structure. At the connections of the roof structure to the wooden beam ceiling, no consistently good result could be achieved. By means of subsequent remedial work, leaks could be reduced but not completely eliminated.


The application of customized detailed solutions also requires a high level of insight and awareness of the problems on the part of all participating construction workers. So as to be confident with regard to execution, it is advisable for the planner or site manager to spend much time on site for supervision.


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