## 4 Conclusions  
This study suggests that, when applying a shingle roof cladding with two layers of wooden shingles on a ventilated pitched cold roof, the following aspects should be considered:  
1. The major source of wood moisture in the studied clime (alpine climate) is precipitation. Whereas the upper shingles' moisture content is directly affected by the rain (rain peaks correspond to peaks in EMC_w_u_m in Figure 9), the lower shingles' EMC is much less affected due to the shield of the upper shingles. The dry-out of the upper (outer) and lower shingle layer is predominantly affected by the ambient climatic conditions. In this respect, measures to enhance the shingles' dry-out to the outer side are very effective. This is, for example, achieved with wooden shingles with spiral grain twist when they dry [4]. 2. The application of ventilation layers under wooden shingle roofs (i.e. cold roof constructions) are preferred compared to unvented (warm roof) constructions because the average wood moisture content is lower in this case. Reducing the air speed in the ventilation layer by blocking the air inlet at the eaves results in a higher EMC and is not recommended. 3. The location of the building and the cardinal point of the roof orientation are of great importance. The current investigation focused on the alpine climate of central Europe and a roof of western orientation (with low solar irradiation). On a roof facing north or which is overshadowed, the solar irradiation and dry-out of the lower shingle layer to the top are lower, and the effectiveness of the ventilation layer underneath is of greater importance. 4. Effective ventilation depends on control of ambient air temperature, shingle surface temperature, and relative humidity in- and outside of the construction, and it was shown that, in the current study, the lower side of the shingles took up moisture from the ventilation air in a daily cycle 45% of the time. This effect was strongest between mid-April and the end of October (high water vapour pressures). 5. It is recommended to ventilate shingle roofs, but a slightly lower average wood moisture content could be realized if the ventilation layer is closed when the inflowing air wets the shingle lower surface (due to condensation or moisture absorption). The effectiveness of this measure is low (\(-0.3\%\) of EMC on average) and would hardly justify the effort for an opening and closing mechanism. 6. The EMC of the shingles (upper and lower layer) rises to a high level (40-80% according to the model applied) during the winter time and temporarily during the summer. Effective ventilation helps to quickly dry out the shingles in the lower layer in the spring time. Moreover, wooden shingles as a roof cladding in the alpine climate repeatedly show a moisture content which favours the growth of microorganisms. Roof claddings are a borderland for wood use, which requires an integrative application of strategies to lower the shingles' moisture content. The interactions with building physical processes occurring when the attic space is conditioned need to be studied in further research. Likewise, the wood moisture content in this study was estimated using a numerical model and has to be verified in an experimental study. Finally, the study has strong implications for the preservation and renovation of traditional wooden roof claddings in the preservation of cultural heritage buildings. If wooden shingles are considered for the application on traditional buildings, ventilated cold roofs are recommended. Conceptualization, G.K. and F.I. ; formal analysis, G.K.; funding acquisition, F.F., R.R., and L.K. ; investigation, G.K. and F.F. ; methodology, G.K.; project administration, R.R. and L.K. ; software, G.K.; validation, G.K.; writing--original draft, G.K. and F.I. ; writing--review and editing, G.K., F.I., F.F., R.R., and L.K. All authors have read and agreed to the published version of the manuscript. This research was supported by the Slovak Research and Development Agency under contracts no.