| Conceptual Reference Database for Building Envelope Research |
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| Essay:Moisture accumulation and dissipation in building envelopeA brief survey [by G. Desmarais, 2000 ]] Moisture found in building envelope could originate from indoor, outdoor or from the materials and construction. The main indoor moisture sources for residential buildings are the occupants and their activities. Outdoor moisture sources are the precipitation and the humidity in the air. The initial moisture content of the building materials, water stored during construction, and incidental water entrances (such as flood) are also important sources. The relative importance of these sources depends on the climate to which the building envelope is subjected. For example, in the mild and humid climate of Vancouver, rain is a more critical factor than moisture transfer from exfiltration. In the cold northern region of Montreal, avoiding moisture accumulation from indoor moisture sources is of more importance.
To control the moisture accumulation in the building envelope, the outside moisture sources must be prevented from reaching the moisture sensitive materials of the assembly; moisture present in the wall must be allowed to evacuate or dry out; and the exfiltrating moisture must be prevented from condensing on interstitial surfaces.
Moisture accumulation and dissipation in building envelope Moisture carried by exfiltration Moisture transport by Diffusion in buidling envelope
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