Every homeowner faces challenges in controlling moisture. Humid conditions from Alpharetta to Buckhead can contribute to the growth of mold and mildew when water vapor seeps into a home over the years. These conditions can compromise both indoor air quality and the integrity of your home’s foundation. If you want to limit the flow of moisture, installing vapor barriers in the crawlspace and other areas of your home is a wise move to make. Here is help deciding if you need a vapor barrier and what it takes to install one.
Vapor Diffusion Retarders and Barriers
The term “barrier” is often used, but materials that control the advance of moisture are more accurately called vapor diffusion retarders. Energy.gov lists the three classes of vapor diffusion retarders and their rankings in terms of moisture permeability (perms):
- Class I includes rubber membrane and glass (0.1 perms or less)
- Class II includes polystyrene and 30 lb. asphalt (0.1 to 1.0 perms)
- Class III includes cellulose and house wrap (1.0 to 10 perms)
If you hope to control moisture in your home, these vapor barriers can be installed in walls, flooring, basements or crawlspaces. To succeed in limiting dampness, you must back up installation of vapor barriers with proper air sealing at different points of your home. A comprehensive energy audit will provide you with a plan of attack to address home performance on every front.
Installing Vapor Barriers
Though vapor diffusion efforts are easiest to achieve in new constructions, there are ways to upgrade the moisture barrier in any home. Atlanta-area homes come into contact with high levels of moisture from the air, which means a combination of vapor and air barriers makes sense. Polyethylene plastic sheets, foil and foam board insulation are three types of materials that provide a barrier to humid air and water vapor.
Air and vapor barriers are installed just before a home’s exterior. In some cases, they may serve as the exterior, and they only do their expected job when leak sealing is part of the job. Polyethylene tape or caulk may be used to seal areas around the window, electrical outlets, doors and any other spot where air can sneak inside your home. Because periods of high heat and humidity present the biggest challenges for moisture control, careful leak sealing is the key to successful damp control.
Managing Crawlspaces
If your home has a crawlspace, a polyethylene ground cover of 6 millimeters in density is recommended for controlling moisture. This step will limit the natural moisture of the earth from seeping inside your home. To protect the integrity of the polyethylene barrier, you may opt to cover it with a 2-inch layer of concrete. Finally, create a downward slope in the soil so the earth’s natural moisture slides away from your home. This last step ensures that vapor barriers can do their job with maximum efficiency.
True moisture control is achieved through a comprehensive effort to identify leaks and stop damp from entering your home. Let Reliable’s home performance experts help keep your home free of mold and mildew with a full range of efficiency upgrades.