Stochastic simulation of rain intrusion through small defects due to water rivulet overpressure. Introducing a driving rain leakage potential

Abstract There is a need of upgrading the old building stock with respect to thermal insulation envelope and specifically façades. are several systems on market, some quite new innovative. To bring down cost many based prefabricated moisture tight insulated units. This means that in case there barrier interior side, two barriers surround wall structure. The leakage driving rain into structure then represents major threat durability these systems. paper investigates pressure build up water rivulets running façade acting together wind pressure. A potential introduced. Using real weather data years Monte Carlo Simulations, mean standard deviation annual through small hole estimated. examples show can reach level 0-0.5 liter/year for diameter 1-2 mm, 0.5-3 3-4 mm.