Getting a radon system put in: what Illinois homeowners should know

Most radon systems are a sealed pipe and a fan. They pull soil gas from under the floor and send it outside above the roof. Many installs are done in one visit.

How does a radon system work?

The most common kind is called sub-slab depressurization. A pipe runs from under the concrete floor to the outside, and a fan runs all the time to pull air from under the foundation. That pulls the radon out before it can get in through cracks, gaps, or the concrete itself.

Because the fan never shuts off, it uses some electricity. How much depends on the fan and the system. Illinois requires the written proposal to include an estimate of the yearly operating cost. The system also has a pressure gauge, called a manometer, or another indicator that shows the pressure or whether the fan is working. It is not a radon detector. It can't tell you the radon level in your home, so you still need to test.

What happens before and during the install?

Before drilling, the licensed installer looks over the foundation, the floor, any crawlspace, the home's mechanical equipment, and the layout. If nobody knows what is under the floor, Illinois requires a communication test, which checks how air moves under the slab, before the proposal is finished. What the installer finds decides where the suction points go, which fan to use, and where the pipe runs.

A typical job has:

• One or more suction points, or another approved setup that fits the foundation
• A pipe, sealed for good, that carries the soil gas outside and lets it out above the roof
• A fan in an approved spot: the attic, a garage with no heated or cooled rooms above it, or outside. Never in a basement, crawlspace, or heated or cooled room
• Sealing where pipes and utilities go through, at slab cracks we can reach, and where the floor meets the wall, plus an airtight sump cover when the system uses or affects the sump
• A pressure gauge or other indicator, the Illinois mitigation tag, and the required pipe and circuit labels

How long it takes depends on the foundation, finished rooms, electrical work, where the pipe goes, and whether the home has more than one foundation section.

What does Illinois require?

The Illinois radon rules are in 32 Ill. Adm. Code Part 422. Section 422.150 covers systems in existing homes. Anyone doing mitigation work needs the right IEMA-OHS license before they start. Our Illinois mitigation license number is RNM2018212.

Before work starts, you accept a written proposal. It has to list the license number, the work, when it should be done, who maintains what, a firm price, the estimated yearly operating cost, and either the terms of a radon-reduction guarantee or the reason there isn't one. When the job is done, the installer gives you information about the system and how to reach them, and keeps the required inspection, design, test, contract, and warranty records. Keep your proposal, system description, operating instructions, warranty, and the test result from after the install with your home's papers.

What do you do once it's running?

Illinois says the test after the install starts once the system has run at least 24 hours, and no later than 30 days after the install. Our guide to test results covers who can run that test and when to test again.

Glance at the gauge now and then to make sure it is in the marked normal range. Keep in mind the gauge does not measure radon. Retest at least every two years and after major changes to the building, as Illinois calls for. If the gauge reading changes, the fan sounds different, or a later test goes up, call a licensed mitigator.

Our written warranty covers the service visit, the labor, and a new fan if a fan we put in fails in its first five years. A fan we replace under that warranty gets its own five-year term. You get the full terms in your customer packet.