Methods of Radon Mitigation
We have several proven methods to reduce the radon level in your home. The two most common methods we use are Active Soil Depressurization(ASD) and Sub-Membrane Depressurization (SMD). We will design and install a system for you based on many factors. These including such variables as current radon levels, size and footprint of your home, foundation design and the type of soil to name just a few.
The specially designed radon fans for the active soil depressurization that we use are very quiet and efficient. In most cases, the fan will use less power that a regular 100 watt light bulb.
We also have other methods available to us when neither a ASD or a SMD will effectively lower your radon level. However these systems are more expensive than ASD and SMD. Statically speaking ASD and SMD will fix the radon problem in 99% of the homes in the Midwest.
Active Soil Depressurization (ASD)
is the most common method used to reduce radon levels. First the basement concrete floor is sealed up. This consists of caulking cracks, sealing up the sump pump hole if one is present, and filling in any holes in the concrete. We then drill a 4.5 inch diameter hole into the concrete slab. From there we remove the material below the slab in order to create a suction pit. Then a 4 inch PVC pipe is inserted through the slab. We install a trim ring around the pvc and caulk the materials together. The PVC pipe is then routed up and exhausted a min of 12" above the roof line. A specially designed in-line fan is installed outside of the house or in the attic. The fan creates a slight vacuum below the slab in the suction pit. This suction captures the radon gas before it enters your home. The gas is then discharged into the air above the roof line, where it quickly and safely dissipates. The PVC pipe can be routed on the outside of your home but we typically will route it through the inside through existing walls, closets and other areas. We will enclose the pipe so it is not visible if desired. A U tube manometer is also installed so that the homeowner can easily check to ensure the system is operating properly.
Sub-Membrane Depressurization (SMD)
works basically the same as ASD. A SMD system is used where there is no slab such as in a crawl space. An airtight poly vapor barrier is placed onto the dirt and sealed around the edges. A vacuum is then drawn using a specially designed in-line fan from below the poly to create a suction on the soil below. The gas is then routed out the roof the same way as and ASD system. In some cases, a combination of both systems are used together.
Air to Air exchangers
This method exchanges air from the contaminated area and exchanges it with air from the outside.