What is a Closed System?

For the past few decades, installing an interior French drain meant leaving a safety slot open around the perimeter to allow water to enter the system through the top. This seemed like a logical, and even innovative idea at the time. Why not give water a chance to enter from above? It was convenient and allowed homeowners to get away with doing minimal repairs by catching the water after it came through the wall instead of STOPPING the water before it reached the foundation. BUT, in recent years we have learned that despite the conveniences that an open system provided, there were many more negative effects that came with them. With an open safety slot, not only can water enter the system from above, but vapor can EXIT the system from below. Between 15-20 gallons of water vapor enter a home through the foundation EVERY DAY! This elevates moisture levels in the home, which leads to increases in:

  • Allergies
  • Asthma/Lung issues
  • Sleeping problems
  • Insect Activity
  • Rodent Activity
  • Mold Growth

Both the CDC and The American Lung Association recommend maintaining a 50% or lower Relative Humidity level in your home, AND recommend ventilating polluted indoor air with fresh outdoor air. This will reduce the negative effects of moisture on your home and family.
http://www.lung.org/healthy-air/home/resources/keep-pollution-out-of-your-home.html

In addition to moisture, RADON can also enter your home through an open system. Radon is the second leading cause of Lung Cancer in the U.S. http://www.cancer.org/cancer/cancercauses/othercarcinogens/pollution/radon

Radon breaks down into other elements. During the breakdown process, alpha particles are released. This is radiation, and it can damage your cells DNA. So if you have radon, you have radiation in your home. What level of radiation is acceptable to you and your family? Radon enters through openings and weaknesses through your foundation walls and floor. Installing an open system is essentially creating a freeway for radon. Open systems can also compromise the effectiveness of existing Radon Remediation Systems.

So now you know that an open system is bad, so what is the alternative?  The only good alternative is a CLOSED SYSTEM.  A closed system is 90% identical to an open system, so that there is ZERO LOSS in it’s ability to capture ground water. BUT with a closed system, we adda layer of  HDPE (High Density Poly Ethylene) sheeting that is sealed against the foundation to prevent moisture in the form of Water Vapor, and RADON from entering your home through the French drain. Both the HDPE sheeting, and the sealing tape are impermeable to moisture and radon. We offer our Standard Closed System, which is an 18″ high layer of HDPE, or our optional FULL WALL CLOSED SYSTEM which runs from floor to ceiling. It is important to make sure that you have addressed all surface water issues properly when installing a standard closed system, as water from above will not be able to enter the system. The cost of addressing your moisture issues may seem high, but the cost of NOT addressing them is MUCH higher.