Consideration of driving rain penetration in hygrothermal simulations of half-timbered walls

Abstract

This paper deals with the consideration of driving rain penetration in exposed half-timbered walls within hygrothermal simulations. On the basis of a real damage pattern, a model is created which forms the basis for a parameter study. The aim of this study is to find out how the penetration of driving rain can be represented in such a way that the damage can be explained by it. For this purpose, (i) a moisture source that depends on the wind-driven rain is increased in intensity according to the standard, (ii) pulses of increasing intensity as well as (iii) constant moisture sources again increased by a factor are implemented. The results show that with the assumptions made, a local moisture source has little effect on the overall water content of the structure. However, depending on the moisture source intensity, a local damage risk for the wood near the joint could be observed. The damage of the case study can be derived, at least in part, from these results. The approach of assuming 1% of the driving rain as the moisture source does not seem to be sufficiently dimensioned. Quantifying the moisture sources for an exposed truss wall is a task for further investigation.