Berkshire Radon Technologies LLC

What Is Mitigation?

A radon mitigation system draws radon away from your home, and vents it harmlessly into the atmosphere. The basic idea is to prevent the radon that may be emanating from the ground from getting into the house. We do this by reaching down under the house with a pvc pipe (a “suction point”), running the pipe up and out of the house until it ends just above the roof. Somewhere in the run of pipe is a radon fan, which creates a vacuum field under the house, pulling the radon gas, as well as other gases and moisture, out from under the house and venting it above the roof.

We install either an Active Soil Depressurization (ASD) System or Sub-Membrane Depressurization (SMD) System. Both of these work the same way. The difference is whether we can go under the basement floor (slab) or if we have to install a radon-resistant membrane over a dirt floor or crawlspace. Sometimes a system uses a combination of the two methods. For instance if there is both a basement and a crawlspace, there would have to be a suction point in both the basement and the crawlspace. These would then be connected to the same exhaust pipe. It is sometimes necessary to install more than two suction points, and in a few cases more than one fan may be required (“double system”), for instance if the basement is very large, or there are many sections with footings preventing air communication throughout the basement.

In locating the pipe and the fan, we consider the structure and aesthetics of the home. Usually we run the pipe from the floor to the top of the basement, out through the band joist, and unobtrusively up the side of the house. The fan would be located outside, just above ground level. In other cases, we can run the pipe up through the house (say, through closets), placing the fan in an non-livable attic, with the exhaust pipe exiting through the roof. Each system has its pros and cons. [link: photos]

NOTE: Once a system is installed, it must run all the time. The radon fan is very quiet and efficient, and costs about as much as a light bulb to run. Turning the system off and on will shorten the life of the fan, which has a 5-year manufacturer’s warranty.

We are your local company for radon —
Serving Massachusetts and New York.


Left: outdoor run – exhaust pipe goes out at top of basement, fan is outside near ground level and exhaust pipe is run up the outside of the house.

Right: indoor run – the exhaust pipe is routed through the inside of the house, with the fan in a non-liveable attic; exhaust pipe then exits through the roof.

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How radon enters a home.
From the EPA publication,
“A Citizen’s Guide to Radon”

Copies available here


A U-tube manometer
indicates if the radon system is functioning