Crawl Space Conversion

June 14, 2017

Crawl Space Conversion

Closed versus Vented Crawl Spaces

Why Close your Crawlspace?

There has been a great deal of debate on whether to vent or close a crawlspace. Vented crawlspaces worked great until the invention of air conditioning. When a family cools their home to 72° during the summer and the air outside is 85° with a 80% relative humidity, it creates condensation on the floor joist, the insulation and the pipes and ducts. No amount of ventilation will solve the problem at this point. This constant condensation during the summer months causes wood rot, mold, and attracts all types of insects including termites.

Closing your crawlspace (which includes sealing the vents, insulating the walls, creating a vapor barrier and conditioning the air in the crawlspace) is now the standard for LEED homes, NAHB Green homes and will probably be part of the building codes in the near future. The leading research on this subject was performed by Advanced Energy under a grant from The U.S. Department of Energy.

This research identifies the common symptoms of a crawl space moisture problem as:

• Mold or moisture damage in the crawl space or living area
• Musty odors in the living area
• Condensation (“sweating”) on air conditioning ductwork or equipment
• Condensation on insulation, water pipes or truss plates in the crawl space
• Buckled hardwood floors
• High humidity in the living area
• Insect infestations
• Rot in wooden framing members
Closing the crawlspace creates a clean conditioned space under the home provides the following benefits:

• Improves air quality throughout the home
• Becomes an Energy resevoir
• Saves up to 18% in heating and cooling cost in the Southeast
• Reduces mold and wood decay on floor joist
• Reduces buckling of hardwood floors
• Creates warmer floors in the winter
• Reduces pest and termite infestation significantly
(dramatically reduces sae harbor for stink bugs in the mid atlantic states)
Over 80 million homes in the US are currently built over crawlspaces. 18% of all new homes built in the US are built on crawlspaces. Our goal at is to significantly improve families’ quality of life, save them millions of dollars in energy usage and make the job of maintaining pest-free homes easier. Please give us a call to find out more about closed crawlspaces and our line of crawlspace products.

Crawlspace Conversion Process

Some of the structural alterations that will be done to convert a vented crawl space to a closed crawl space involve sealing vents and installing a sealed vapor barrier on the crawl space floor. This moisture barrier is extended up the interior foundation walls of the structure. All water or moisture sources must be dealt with. On some homes we may also install insulation on the interior foundation walls. We view it as a necessity to insulate the crawl space if you are going to ecapsulate and do a vapor barrier.


Closed Crawlspace:

  Vented Crawlspace:

  • Crawl space moisture sources reduced or eliminated
  • Moisture barrier is installed
  • Vents are sealed
  • Crawl space insulation is added according to site conditions
  • Crawl Space entry way is insulated and sealed with a product like crawl space zipper from Attic Zipper.

Above: Automatic-opening crawl space vent

Above: Always-open crawl space vent

If you are interested in more information on crawl space conversion and information on reasonable contractors known to be well established as professionals in crawl space insulation, vapor barriers and encapsulation, Click this link and fill out the form we will give you the local contractors information who is in our database.   We wont give your information to contractors, contacting them is up to you..