In homes with raised foundations, moisture barriers should cover what percentage of the exposed ground surface?

In homes with raised foundations, it is crucial for moisture barriers to cover a significant portion of the exposed ground surface, as this helps prevent moisture from seeping into the structure. A coverage of 75 to 80% is recommended to effectively reduce the risk of excessive humidity and potential water damage, which can lead to mold growth, deterioration of building materials, and reduced indoor air quality.

By covering a substantial portion of the ground, moisture barriers can effectively mitigate moisture accumulation, thus enhancing the overall integrity of the home. Achieving this degree of coverage ensures that most of the exposed soil is protected, minimizing vapor transmission into the crawl space or foundation area. Such measures are key in maintaining a dry environment, which is essential for the longevity and health of the home.

The other options suggest insufficient coverage, which would not adequately protect the home from moisture intrusion, increasing the potential risks associated with mold and structural damage in the future.