This article will show you how to add 6 mil plastic sheeting on the ground and insulate the walls in your crawlspace. We use foil-faced rigid insulation to keep the space under the house dry. The plastic and the insulation will eliminate any moisture problems you have in the crawlspace, such as water droplets collecting on the concrete walls and pipes.
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.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.