Andy Lang will present the investigation of the reported moisture problems, including site investigation and monitoring of temperature and humidity conditions within the wall assembly, the unit interiors and the exterior of a recently constructed precast concrete clad residential tower near Seattle, WA.   Hygrothermal modeling was undertaken using both default environmental conditions and actual measured data, to assess the risk of condensation based on the as-built assembly and to aid in verifying the suitability of proposed repairs.

Specific exterior wall assembly and the detailing and conditions that contributed to the condensation problems will be discussed.  Initial dew point analysis that was undertaken during the design phase will also be presented, which predicted condensation occurring in the assembly if air leakage into or across the assembly was not controlled.  Finally, Andy will outline the repair strategy executed to address the condensation problems.