The Alte Schäfflerei of the Benediktbeuern monastery dates from the second half of the 18th century and is therefore a listed building. The baroque hipped roof and the supporting king post construction are particularly striking. When the wooden beam ceiling was opened up, however, it became apparent that almost all of the beam heads were severely infested with wood-destroying fungi.
Which is the best renovation method for the wooden beam heads? Measurements taken after the restoration showed that the moisture content in all beam heads is in an absolutely uncritical range - all measurements taken last year were below 16 mass percent. The differences in the type of support used, i.e. mortar, elastomer or nanogel, as well as in the beam head insulation and cavities thus seem to play a minor role. No clear conclusions can be drawn about the renovation method via the moisture curves. Although the beam head with the integrated copper sheet as a thermal bridge has the highest surface temperatures, this does not necessarily mean that the wood moisture content would be lower than in the other beam heads. Irregularities in the wall seem to play a greater role than the renovation methods.
To verify this, the researchers used WUFI® 2D to recalculate the moisture curves in the beam head for three of the renovation methods. The outdoor climate parameters measured in the vicinity, as well as those of the indoor climate, served as the general conditions. The calculations confirmed the results obtained by measurement, i.e. the renovation methods themselves only play a minor role in this case. The research results show: The system of the wooden beam head integrated in the wall is much less critical than expected. In most cases, the damage that is repeatedly found on beam heads is most likely due to unexpected incidents occurring during the life of the respective building - such as a leaky roof, a leak in the water supply or similar. Thus, it is almost impossible to do anything wrong when renovating damaged wooden beam heads, provided there is adequate external rain protection.
