The traditional approach to crawlspaces is to leave them outside of the building envelope by insulating the floor between the house and crawlspace.

Enclosing a crawlspace is an alternative approach. Exposure rated rigid foam and spray foam are used to seal and insulate all foundation walls and rim joist areas. A new ground cover is installed and a fan is installed in the crawl space that is vented to outside.

There are several advantages to an enclosed crawlspace, and one disadvantage.

Advantages:
  • Indoor air quality is improved by reversing the stack effect. Instead of air rising into the home from the crawl space (poor air quality) air is pulled into the crawl space from the home. This can greatly reduce high humidity in your home and eliminate that unpleasant smell of crawl space.
  • Humidity is reduced in the crawl space and condensation eliminated. A warmer crawlspace that is well sealed will almost never fall below the dew point, even on cold surfaces like copper pipes.
  • Ducts do not need to be sealed and insulated. Insulating ducts can be a significant expense that is avoided when the crawl space is part of the conditioned space.
  • Water pipes do not need to be insulated.
  • Enclosed crawl spaces are warm, clean, and do not have exposed fiberglass. This makes them more attractive for storage. Just don’t damage the ground cover.

Disadvantage:

  • Lower energy savings compared to traditional floor insulation. Well installed floor insulation (paired with proper air sealing) will make your home more efficient because you are conditioning a smaller volume compared to an enclosed crawlspace.

Contact CAZ Construction at 360-389-1056 and find out if an enclosed crawl space is the right choice for you.