Services We Recommend

Brabble Insulation – Ahoskie, NC – 800-526-0839
www.brabbleinsulation.com

Conditioned Crawl Spaces


Many homes built on crawl space foundations in the Southeastern United States suffer from poor moisture management. Some of the common symptoms of a crawl space moisture problem are:

  • 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

These symptoms are most often noticed in the humid spring and summer seasons but can occur at any time of the year. Often, the heating and air conditioning contractor is the first person the residents call to deal with the problem. Typically though, the problem is not due to a failure of the air conditioning system; it results from poor moisture control in the crawl space.

For many decades, building codes and conventional wisdom have prescribed ventilation with outside air as the primary method of moisture control in crawl spaces. In the humid Southeast, however, ventilation with outside air only makes moisture problems worse. Recent research by Advanced Energy and others indicates that a new type of crawl space system, with NO vents to the outside, can provide greatly improved moisture control and significant energy savings when properly installed.

There are several ways to close and condition a crawl space. Following is brief detail of how we do it at Brabble Insulation.

  1. First we lay down ,a minimum, black 6 mil vapor barrier. (vapor barrier ugrade options are available) This vapor barrier covers the ground 100% with approx. 8” going up the foundation walls and pillars. The overlap of the vapor barrier is at least 6 inches and is sealed. 
  2. Then we spray 1-1/2" to 2" of foam to the foundation walls from the sub-floor down to the ground level, sealing the 8” lap to the wall. Any foundation vents are blocked off and sealed. This prevents nearly all outside air from going under the house and causing condensation problems. No water will pass through the foam and any moisture that passes under the foundation will be trapped under the vapor barrier. If you are having severe water issues under the house, it may be necessary to do some landscaping or put down a drain tile. 
  3. We do recommend that one 4” duct line be tied into your supply duct work under the house for every 1500 sq. ft. so that when the unit comes on, it will circulate some air under your house. A 2” to 3” area of the foundation wall perimeter will not be foamed and will serve as a termite inspection area. (as per code