How should the vapor retarder be installed at the crawl space wall and piers?

The correct installation method for the vapor retarder at the crawl space wall and piers is to turn it up to the crawl space wall and piers and seal it. This approach is essential for preventing moisture from the ground from entering the crawl space, which can lead to mold growth, wood rot, and other moisture-related issues.

When the vapor retarder is extended up the walls and sealed, it helps create a continuous barrier that significantly reduces the movement of moisture-laden air and water vapor into the crawl space environment. This sealing is critical as it not only blocks moisture but also helps maintain the appropriate humidity levels within the crawl space, which is vital for the structural integrity of the building and the comfort of the inhabitants.

Placing the vapor retarder flat on the ground would not provide adequate protection, as it would not address the potential for moisture to rise up the walls. Hanging it loosely from the ceiling would also be ineffective as it does not prevent moisture movement from the ground. Installing it vertically along the walls wouldn't provide the necessary coverage and sealing that is crucial for effectively managing moisture intrusion. Hence, correctly sealing the vapor retarder at both the wall and pier interfaces is key to achieving a moisture-resistant crawl space.