Moisture Barrier Installation
If you have water collecting on the pipes and concrete walls in your crawlspace, then you’re experiencing a common problem. The ventilation openings were designed to flush out moisture from crawlspaces, but they often don’t do the job, except in dry climates. In fact, during humid summer conditions, they often make matters worse. The humid air carries moisture that condenses on the cool walls, the pipes and even the underside of floors.
The best solution is to completely close up the vents (or omit them in new construction) and control crawlspace moisture in other ways. The photo illustrates several key concepts. However, local and regional conditions vary and the exact details of this system may not work in every crawlspace. Make sure to get approval from your local building inspector before taking any steps.
Create good drainage around your home to keep rainwater from flowing in under your house. Sloping the soil away from your home at about 1/2 in. per foot is usually the best thing you can do to reduce crawlspace moisture.