Volume 39, Issue 4 (July 2011)
Condensation Problems in Precast Concrete Cladding Systems in Cold Climates
The use of precast concrete panels as a cladding material can provide an economical and attractive method to enclose contemporary buildings. In cold climates, improper detailing or inappropriate construction of precast clad walls can result in widespread water problems due to condensation forming within the wall construction. Condensation may form at the interior of the wall assembly due to inadequate protection against air flow through the wall, such as exfiltration of warm, moist indoor air, or by infiltration of cold outdoor air reaching the interior wall components. The condensation within the wall assembly can also be caused by water vapor diffusion into the wall from the building interior. In addition, inadequate separation and/or insulation between precast panels and adjacent cladding components, such as windows, curtain wall, or metal framing components, can result in surface condensation on these wall elements. The moisture from condensation can cause extensive damage to finish materials, including insulation and gypsum wallboard; can result in corrosion and deterioration of metal components, such as structural connections and metal wall framing; and may result in mold and mildew. This paper will (1) present examples of precast clad building wall construction where significant condensation problems have occurred; (2) discuss typical causes of condensation in precast clad buildings in cold climates; (3) review design considerations to reduce the potential for condensation in new buildings; and (4) present repair methods to address condensation in existing buildings.