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When it comes to choosing crawl space vapor barrier sizes, it could be a little confusing if you don’t know what to look for.

Crawl space vapor barriers are built in a variety of different sizes, some as small as 6 mil and as large as 20 mil. Also referred to as a crawl space liner, the larger the size, the more protection the vapor barrier provides.

The 20 mil vapor barrier and 12 mil vapor barrier is two of the most common crawl space sizes used.

While some people choose to go with the 20 mil and 12 mil for precautionary measures. some crawl spaces need it due to the condition of their crawl space floors.

If you have a tough crawl space floor that contains rocks, objects or any other obstruction, you’ll likely want a 12 mil crawl space vapor barrier or a 20 mil crawl space vapor barrier.

On the other hand, if you have a smooth crawl space, small crawl space, you may be able to use a 10 mil, 8 mil or 6 mil vapor barrier.

The 5 most common crawl space vapor barrier sizes include the 20 mil, 12 mil, 10 mil, 8 mil and 6 mil crawl space vapor barriers.

20 Mil Crawl Space Vapor Barrier

  • Used in large crawl spaces
  • Used on the crawl space floor
  • Used for hard crawl space floors with large rocks, large objects in the way
  • Foot traffic and storage should be fine
  • Make sure it’s built for crawl spaces

12 Mil Crawl Space Vapor Barrier

  • Used in large and mid-sized crawl spaces
  • Used to protect both crawl space floors and walls
  • Several types are available
  • Medium storage and foot traffic
  • Make sure it’s built for crawl spaces

10 Mil Crawl Space Vapor Barrier

  • Used in small and mid-size crawl spaces
  • Used to protect crawl space floor
  • Crawl space floor should can be a little rough, very small rocks
  • Be careful of brand, don’t go cheap
  • Very little foot traffic or storage
  • Make sure it’s built for crawl spaces

8 Mil Crawl Space Vapor Barrier

  • Used in small crawl spaces
  • Used to protect crawl space floor
  • Crawl space floor should be clean
  • Be careful of brand, don’t go cheap
  • No foot traffic or storage
  • Make sure it’s built for crawl spaces

6 Mil Crawl Space Vapor Barrier

  • Used in small crawl spaces
  • Used to protect crawl space floor
  • Crawl space floor should be smooth and clean
  • Be very careful of brand, don’t go cheap
  • No foot traffic or storage
  • Make sure it’s built for crawl spaces