A major factor contributing to loss of energy, moisture issues and ice dams is warm air leaking up into the attic. When this happens, air and moisture is drawn up through the house. This creates a negative pressure condition in the lower levels.
Your house acts like a chimney where warm air rises and escapes in the attic through any gaps or penetrations of the homes envelope. When this happens cold air enters the lower areas of the home. A home with a leaky envelope is a home that is cold and drafty. A house with a poor and leaky envelope will show significant heat loss through the attic and eaves (as is shown on the right). When the conditions are right this will also lead to ice dams that can be very damaging to the roof.
With our air leakage services we have seen some impressive results. We will typically see over a 15% improvement in air leakage, by tactically sealing up the gaps. In some situations we have improved things by over 50% . This is over and above the benefits you'll see from conductive losses and having greater insulative R values in your ceiling and walls.
This thermal image shows energy leakage into the attic that is then escaping through the soffit vent.
This chart illustrates the flow of energy and air within the home.