Case Study Repair of Shadow Box Spandrel Condensation

摘要

Most people naturally assume that water leaks are caused by exterior precipitation. However, when the reported water leaks are not coincident with rain or snow, other factors, such as interior condensation, need to be considered. Curtain wall construction is susceptible to condensation if interior ambient humidity can reach cold metal or glass surfaces. Shadow box spandrels- spandrel panels built with vision glass and recessed back panels to give a sense of depth to the spandrel glass-introduce multiple planes where such condensation could occur. Condensation on internal shadow box surfaces, such as the metal back panels, can lead to water leaks inside the building. Condensation on the interior surface of the shadow box glass may also be visible and unattractive from outside the building. This paper details one case of internal condensation in curtain wall shadow box spandrels. The paper describes the initial leak investigation, the repair options evaluated, laboratory testing to assess the repair options, and how the repairs were implemented. Lessons learned from this case study are offered for future curtain wall designs of similar construction.