High-performance weather-protective flashings

Typical problem areas associated with weather-protective flashing are identified, based on a comprehensive investigation of building damage cases in Norway. A total of 175 assignment reports associated with damaged flashing for the period between 1963 and 2001 are analysed. The investigation clearly shows that certain faults and deficiencies are recurring items. Windowsill/weatherboard flashings comprise as much as 41% of the building damage cases associated with weather-protective flashing. Damage in connection with parapet flashing comprises 27% of all cases included in this investigation. With few exceptions, instances of damage are located in Norway's coastal areas. Existing flashing solutions in the Norwegian Building Research Institute's Building Research Design Sheets have been further developed, based on the results from the analysis. Improved high-performance flashing solutions are presented for a number of typical problem areas. An illustrated summary of problems frequently encountered with different flashing variants is also presented. Finally, recommended best-practice flashing solutions for a number of typical problem areas are provided. The results will be implemented in the Building Research Design Sheets, and will also be used as a basis for the carrying out of new field studies and laboratory investigations.