Preventing the formation of condensation within wall cavities, attic spaces and cathedral ceilings is one of the primary goals of building science.
Condensation occurs when the dew point is pulled into the building’s envelope. When the air temperature is equal to the dew point temperature, the air can no longer hold the water vapor contained within it and some of the vapor condenses into liquid water.
If the relative humidity is 100%, the dew point temperature and the air temperature are equal, meaning condensation will form. This occurs within a building’s envelope when the rate of moisture entry into the assembly exceeds the rate of moisture removal, causing an increase in relative humidity.
The basic strategies to minimize the risk of moisture damage are: control the moisture entry, prevent moisture accumulation and remove the moisture.
The source of moisture may be related to the groundwater below grade, moisture loads within the building itself, water infiltration through the building’s exterior and transitional details, and the physical environment around the building.
Preventing moisture accumulation can be minimized though the rain screen technology and properly vented roof assemblies. Removal of the moisture-saturated materials will help ensure that the rate of moisture entry is less then the rate of moisture removal.
The cost to remediate damage caused by condensation is often quite high and requires building science knowledge and design experience. At Westcoast we have years of experience in this type of design and can assist in even the most complex situation.