NJ License #24GI00173100  




Radon is a radioactive gas that comes from the breakdown of naturally occurring uranium in soil and rock. It is invisible, odorless and tasteless, and can only be detected by specialized tests.


The most common type of radon mitigation system is the sub-slab depressurization system. This system uses venting and sealing to lower radon levels in the home. A pipe is installed that runs from below the basement flooring to above the roofline, with a fan at the top that draws radon out from under the slab. Cracks and openings in the foundation are sealed. The radon is vented through the pipe to the outside, where it is quickly diluted.

The average price of such a system is around $1,200, although prices can range from $500 to $2,500, depending on characteristics of the home and the underlying soil. You can install the system yourself, if you are highly experienced in making home repairs, or you can hire a New Jersey certified radon mitigation company to do the work for you. New Jersey certified radon mitigation professionals meet specified education and experience standards and must take continuing education classes each year to maintain their certification. It is against the law for uncertified contractors to do mitigation work in New Jersey.

After your home has been mitigated, make sure the Contractor does a post-mitigation test to prove the system is working properly. In addition, you can contact the Radon Program to obtain a free post-mitigation test (you will have to provide a copy of your mitigation contract). Retesting your home every two years will tell you whether or not your system is still working effectively in reducing the radon level to below 4 pCi/L. If you believe that your system was not installed correctly, you can contact the Radon Program to arrange for a free inspection and test of the system.

Radon enters homes through openings that are in contact with the ground, such as cracks in the foundation, small openings around pipes, and sump pits.

While there is almost no place in the world where radon isn’t a factor, New Jersey and New York have some areas where there are very high levels of radon so you should have your home tested.

Radon, like other radioactive materials, undergoes radioactive decay that forms decay products. Radon and its decay products release radioactive energy that can damage lung tissue and cause lung cancer.

The more radon you are exposed to, and the longer the exposure, the greater the risk of eventually developing lung cancer. Radon is the second leading cause of lung cancer in the United States, resulting in 15,000 to 22,000 deaths per year.

Testing your home for radon is easy and homes with high levels of radon can be fixed (mitigated). The New Jersey Department of Environmental Protection (DEP) recommends that all homes be tested for radon.

Radon Testing for Real Estate Transactions:

Acorn Home Inspections conducts a short-term, 48-hour radon test which may be used for real estate transactions. In some cases, large buildings will require more than one testing device. If it isn’t possible to obtain results until after closing, an escrow account, with funds set aside by the seller, can be arranged for the buyer who prefers to test after closing. The funds can then be used to mitigate the home if testing reveals concentrations of 4 pCi/L or more.

The testing device will be placed:

·      in the lowest livable level of the home — that is, the lowest level of the home that is used, or could be used, as a living space. This would include, for example, a first floor without a basement, and a finished or unfinished basement, but not a crawl space.

·      in a location where it will not be disturbed.

·      at least 20 inches from the floor, at least 4 inches away from other objects and at least 36 inches away from doors, windows or other openings to the outside. The tests only need to be placed one foot away from exterior walls that have no openings. If suspended from the ceiling, it should be in the general breathing zone.

Test kits will not be placed:

·      in areas exposed to direct sunlight, drafts, high heat, or high humidity; or

·      in kitchens, bathrooms, laundry rooms or closets.

In addition, attic and window fans, fireplaces and wood stoves (unless they are the primary heat source) should not be used for the duration of the test. They will affect air pressure in the house which will in turn affect radon concentrations. Air conditioning can be used if it circulates inside air rather than bringing in air from the outside.

For short-term tests, it is very important to maintain “closed house conditions,” since ventilation can increase or decrease radon levels in unpredictable ways. This means all windows and doors that let in outside air, on all floors, must be kept closed except for normal entrances and exits. You need to maintain closed house conditions until the short-term test is finished. For tests that last less than four days, closed house conditions must be started at least 12 hours before you begin the test.


We use a certified lab in Princeton, NJ to analyze the testing materials. The test report will give your radon reading in picoCuries per liter (pCi/L). PicoCuries per liter is a measure of how much radiation is in a liter of air, which is about the size of a quart. Sometimes results will be given in Working Levels (WL). You can calculate the pCi/L level by multiplying the WL reading by 200.

The DEP and the Environmental Protection Agency (EPA) both recommend that you take action to mitigate your home if your test results indicate radon levels of 4.0 pCi/L of radon or more. If you used two or more short-term tests at the same location, the results should be averaged.

There is no truly “safe” level of radon since lung cancer can result from very low exposures to radon – however, the risk decreases as the radon concentration decreases. If your test result is less than 4.0 pCi/L, you may want to discuss with mitigation companies whether the radon level can be brought down still further. In about half of the homes that have been mitigated in New Jersey, radon levels have been brought to less than 1 pCi/L.