- 40% of the air you breathe in your home comes directly from the crawlspace.
- A crawlspace of 700 square feet can produce 10 gallons of moisture, rising into the floor system EVERY DAY.
- Number one cause of hardwood floors buckling is high humidity levels in crawlspace.
A vented crawlspace has foundation vents allowing air under your home. A vented crawlspace should have temperature and humidity similar to the outside environment. This means that a home that has a vented crawlspace should also have in addition to proper amounts of ventilation, a proper vapor barrier covering the earth as well as the subfloor being insulated.
The problem with vented crawlspaces is that the ground is rarely covered properly. This allows excessive humidity / moisture vapor in the area under the home. Over time the moisture can decay the foundation of the home if a proper vapor barrier is not in place. These moist crawlspaces can also cause insulation that you may have under your home to sag and become less effective. Other problems associated with vented crawlspaces include pest problems, mold/mildew, poor indoor air quality, and more.
We find that most crawlspaces are connected to the living space via holes, cracks, and gaps that allow crawlspace air and moisture to enter your home, introducing contaminants and decreasing air quality. Vented crawlspaces are the main source of high moisture levels in the home. In many cases, the home’s ductwork is located in the crawlspace. Leaks in this ductwork can actually vacuum the crawlspace air up into the house every time the system turns on.
Musty odors, sagging insulation, mold/mildew, and weak spots in the floors of your home are some of the more obvious signs of a crawlspace that may be in need of attention.
Not all vented crawlspaces are “bad” crawlspaces
- Vapor Barrier – A vapor barrier is a sheet of plastic that covers the ground under a home. Vapor barriers, if installed correctly, help resist moisture from the ground which would otherwise work away at the foundation of your home, as well as cause indoor air quality problems. A properly installed vapor barrier should consist of no less than 6 mil plastic over lapped, and taped at the seams, total ground coverage, and an additional 6-8 inches of plastic sealed to the foundation walls.
- Air/duct sealing – since 40% of the air you breathe inside your home comes from the crawlspace, it only makes sense to have your ducts and crawlspace sealed off from your living area. Air sealing a crawlspace consists of using an expanding foam solution to fill all cracks, penetrations, or other potential places where air can infiltrate your home from underneath. Duct sealing typically involves a product know as mastic which is applied to all connection points and seams of the HVAC system, as well as duct work. This ensures that you’re getting the heating and air that you pay for each month, as well as preventing any “bad” air from the crawlspace to be sucked into your system and circulated throughout your home. Not only is duct sealing and air sealing in a crawlspace important to the indoor air quality of the home, but it also saves energy by reducing the amount of time you HVAC unit has to run.