Department of Energy.Īs an added measure, some contractors will recommend also creating an air barrier. The sheet seams will overlap by 12 inches and be sealed with tape, according to the U.S. When it comes to crawl space vapor barrier installation, a contractor will place a 6-mil polyethylene sheet across the crawl space floor and 6 inches up the walls. Crawl Space Vapor Barrier InstallationĪ vapor barrier is part of a moisture control strategy when it comes to your home, and specifically to the crawl space. Installing a vapor barrier in your crawl space will keep the area dry and healthy. This is why a moisture barrier under the house is so important, as it can help prevent that damage and possible hazards.
That water can also cause your plumbing to rust and eventually break over time. Without a vapor barrier, the moisture that comes in through the soil can lead to electrical shorts, which is a fire hazard. Two more things to consider – any mechanicals, electrical, or plumbing you might have running through your crawl space. This can lead to structural damage to your home, including rotting wood and rusted metal. On top of that, if you have fiberglass already in your crawl space without a vapor barrier, then that will retain the moisture. This moisture will lead to mold and mildew growth, which on their own are unhealthy. The thing is, the moisture doesn’t have to come from a leak, because it can come right up through the soil in your crawl space. You don’t want moisture to seep into your crawl space because it can cause a ton of problems. Well, it comes down to nature and science. You’re probably wondering why a crawl space vapor barrier is important if you have dirt floors. In our continued endeavors to educate homeowners, we will break down what the crawl space vapor barrier is, how it’s installed, and the cost. So, what’s the big deal about a vapor barrier under the house, anyway? This is the technique we use when insulating a crawl space with a dirt floor. When we insulate the walls of the crawl space, we lay down plastic over the dirt floor that is a vapor barrier. RetroFoam of Michigan has been insulating crawl spaces with foam insulation for more than 15 years. One of those steps is a crawl space vapor barrier, especially if you have a dirt floor. Your crawl space is a dark, dank space that can be a breeding ground for mold and mildew if the proper steps aren’t taken.