A Vapor Barrier Alone May Not Be Enough

When dealing with high levels of moisture coming from a crawl space, a simple 6mill vapor barrier may not be enough to reduces and eliminate those high levels of moisture. Here is a few reasons why. First we have to look at what is causing the high moisture levels in the crawl space. If standing water is an issue than installing a vapor barrier alone would do little if any to help the matter. In fact with out some type of drainage system and a pit/pump, a vapor barrier alone could possibly make things worse by allowing the water to sit on top of the barrier with no where to go but up into the living areas. If standing water is not an issue than more than likely you are getting the unwanted moisture in your crawl space from 3 possible areas. First would be the crawl space dirt floor. Moisture is always constantly coming out the dirt floor ground in you crawl space. This moisture than moves with the nature air flow of the home, which is from bottom to top, or what some refer to as stack effect. Stack effect is the reason we see moisture in the crawl space causing issues in the living area, such as mold, buckled or warped floors and even moisture on the windows. A simple 6mill vapor barrier laid across the entire crawl space floor will help keep moisture from the dirt crawl space floor from getting into your crawl space of the living areas of the home. The moisture is simple somewhat encapsulated under this barrier. But a 6mill vapor barrier is recommended to be installed a few inches away from the walls due to block seepage and it is not a complete seal of the dirt crawl space floor, so there are still areas that moisture may be able to come up through the dirt crawl space floor. Even with a vapor barrier we still have two other areas that moisture is able to get into your crawl space that a simple vapor barrier cannot address. The second area is the foundation walls. Whether they are block, poured, or stone, foundation walls tend to seep moisture. Although most homes built in the last 40 yrs would have some type of waterproof membrane on the exterior side of your foundation, these tend to not last very long. And areas that have a high water table can cause the seepage of moisture through your block walls to increase as well, adding to the unwanted high moisture levels in your crawl space. The last place your crawl space may be getting moisture from is your vents. Although they were intended to help keep you crawl space dry, they may in fact be doing the exact opposite. Consider this, on a hot humid day in the middle of the summer when your vents are to be open, the outside air has a large amount of moisture in it. When that air comes into your crawl space through vents your simply bringing all that moisture in with it. Not to mention if you have duct work in your crawl space this hot humid air is going to make them and pipes as well sweat, thus creating even more unwanted moisture in your crawl space. So to address all these areas that moisture comes from in your crawl space a simple 6mill vapor barrier may not be enough. The only sure way to permanently seal this outside moisture from getting into your crawl space would be a crawl space encapsulation system. To see more information on permanent crawl space solutions such as an encapsulation system visit www.swaincollc.com