Whenever you hear people talking about insulation, you will probably hear the term vapor barrier thrown in a few times. This barrier is very important, and you should make sure you understand it. It does a lot to protect the warmth and integrity of your home, probably even more so than you think.
Warm air will always move toward colder air, through a process known as convection. This basically means that during the winter the air inside your home will always be trying to escape and move towards the air that is colder outside. Warm air has the capability to hold more moisture than cold air because it expands. Air cools, and while it does, it contracts and loses some of its capacity, given off moisture to cooler surrounding surfaces.
The purpose of a vapor barrier is to prevent the penetration of moisture from one area to another. By placing this barrier between the inside of the house and the insulation, it will act as a physical shield to repel moisture and keep it from entering enclosed spaces where it could do some really bad damage.
The vapor barrier that is between the wall insulation and the interior side of the exterior walls is one of the most important in the home. Wall cavities in your home are sealed and have no means of allowing built up moisture to escape, which makes an effective moisture barrier very crucial in preventing wet air from entering the walls.
To insulate your walls, foil or paper faced insulation is often used. This insulation should be installed between the studs with the vapor barrier facing toward the house.
The most important thing to remember is that the barrier is always installed between the insulation and heated portion of the house. The edge of the insulation is referred to as wings, and should be stapled to the studs in order to be held in place, and create a more effective vapor barrier.
With construction today, these barriers are still used and still remain highly effective. When it comes to moisture seeping in to your walls, a vapor barrier could be the best friend you have ever had. You surely donít want this moisture, simply because it will cause you more harm than good in the long run.