Controlling Moisture 

Stopping air movement also helps to control moisture. Moisture moves with air, so cracks that allow air to enter your home also allow moisture to enter.  While you may not notice the moisture in the air unless the temperature is high, it’s there.

Temperature determines the amount of moisture that air can hold.  Warm air can hold more moisture than cold air, so places where warm and cold air meet present a particular problem.  As air cools rapidly, the volume of moisture becomes too great and that moisture is released in the form of condensation.  If you’ve ever had condensation on your windows in the winter, as warm inside air comes into contact with the cold glass, you’ve seen this happen.

This same natural occurrence can cause significant problems in your home as air moves through the wall spaces.  Warm inside air cools as it gets closer to the exterior wall.  Moisture in that warm air can form condensation in wall spaces in the same way that it forms condensation on a window.  That moisture creates the possibility of mold forming in those wall spaces, creating problems with indoor air quality.  Air sealing can stop the air from moving in these places and therefore keep the moisture out as well.