Avoiding moisture damage
Although energy-saving initiatives have led to significant improvements in heat insulation and sealing off building interiors, these improvements are associated with an increased risk of moisture damage arising from higher indoor air humidity, which enhances the probability of condensate. Adding to this problem, there is less heat available overall to evaporate moisture accumulated in construction components, with the result that other moisture issues such as rainwater, condensation water from outside and trapped humidity pose a greater problem than in the past.
This makes a precise appraisal of hygrothermal conditions and targeted moisture control design more important than ever, accompanied by the search for new solutions and approaches. Most damage can be avoided by careful planning and implementation of moisture protection measures and by choosing the right materials. A traditional means of moisture protection assessment is the Glaser method. However, this method only takes into account condensation formed as a result of diffusion from the interior such as commonly occurs in winter – it cannot evaluate other important factors for many buildings, such as trapped moisture, driving rain and summer condensation.
Today’s hygrothermal simulation software is capable of delivering realistic calculations of all relevant hygrothermal storage and transport processes in components under real climatic conditions. As well as allowing comprehensive moisture control design, this also makes it possible to take the energy effects of moisture into account. Demand for the WUFI® software family first licensed by Fraunhofer IBP in 1995 is growing around the world. Intensive program maintenance ensures that new discoveries in building physics are swiftly implemented and that material and climate databases are continuously updated with new information. In collaboration with many international partners, new functions are being added to the programs all the time, including tools for evaluating leaks, damage mechanisms and ageing processes.