Experimental study on the wind-driven rain absorption of different exterior finishing stone materials

Wind-driven rain (WDR) is one of the sources of moisture in building facades and poses a major threat to the insulation performance and longevity of walls. Studies have been conducted to include WDR in the moisture boundary of building facades, but exactly how much rainwater can be absorbed by the wall is not yet clear. To understand the absorption of WDR by building exterior materials, nine types of exterior finishing stone materials were selected for the study and the absorption of WDR by different materials was measured. The results show that the factors affecting the absorption of WDR include not only physical parameters such as porosity, but also depend on whether the material surface is waterproof, on the amount of WDR during rainfall and on the water saturation of the material. Based on the multiple regression fitting, the WDR absorption ratio calculation model was defined with water content saturation, porosity and cumulative WDR amount as the influencing factors. The model provides a reference for the setting of building simulation parameters for exterior moisture boundary conditions of building facades