The age-old concern of daily life when it comes to homeownership is keeping moisture out of your house. To that end, engineers have gone to great lengths to quantify and improve the methods of preventing moisture from penetrating walls and ceilings. One of these methods is the use of vapor barriers.
Vapor barriers are a layer (or layers) of material enveloping your house that is designed to prevent the transfer of moisture. The materials can be as thin as paint and as thick as blocks, but they all have their own “perm rating” that describes how difficult it is for moisture to penetrate through them.
You should consult a professional if you need to deal with vapor barriers. It’s not always easy to add a vapor barrier to an existing building, and having too many barriers can be just as bad as not having enough. In some areas, vapor barriers can even be a bad idea!