Buying or selling a home in Prescott comes with a long list of inspections. Radon is easy to overlook because it has no color, smell or taste, and the only way to know a home's level is to test. A test during the sale gives everyone the same number to look at before decisions are final.
This page explains how radon testing fits into a home sale, how test conditions are kept consistent, and what your options are if a result comes back high. If you want to talk to a local radon professional, call (928) 582-8914. Callers are connected with licensed and insured local radon testing and mitigation professionals.
Why radon matters in a Prescott sale
Radon is a radioactive gas that forms from the natural breakdown of uranium in soil, rock and water. The Granite Dells granite just north of the city is about 1.4 billion years old and has an unusually high uranium content, according to the Arizona Geological Survey. The Survey also notes that radon from this granite is a concern for people who build weather-tight homes on it.
That does not mean every home near the Dells has a problem, and it does not mean homes elsewhere are safe by default. Any home can have a radon problem, new or old, with or without a basement. The result for one house says little about the house next door, so each home needs its own test.
Testing during the inspection period
Radon tests are often done during the inspection period of a sale, alongside the other inspections. Buyers can use the result to make an informed choice before closing. Sellers can use a result to understand the home and plan ahead, rather than meeting the number for the first time in the middle of a deal.
Homes in Prescott range from Victorian houses near downtown and Whiskey Row to newer subdivisions toward the Granite Dells, Prescott Lakes and Willow Creek Road. EPA recommends testing all homes below the third floor, so the age and style of the house do not change the basic advice. A radon professional will look at how the home is laid out and where to place the test.
How test conditions are kept consistent
A fair result depends on a test that is set up the same way each time. Short-term tests stay in place from 2 to 90 days, and a test done during a sale is usually a short-term test. To keep it consistent, the home is kept in closed-house conditions. Windows and outside doors stay closed except for normal coming and going.
That can be a change in Prescott, where day-to-night temperature swings average nearly 30 degrees and it is tempting to open the house up. The device is placed in the lowest lived-in level of the home. Keeping the setup steady means a result can be compared with the 4 pCi/L action level that EPA uses.
Long-term tests stay in place for more than 90 days and better reflect the year-round average. They are less common during a sale because of the time involved, but they can be useful after a move-in.
Why an old test may not tell the whole story
Sellers sometimes have a radon result from a previous owner. That number is a snapshot of the home on the day it was tested. It may not reflect current conditions, especially if the home has been renovated since. Changes to floors, foundations, ventilation or how tightly the house is sealed can all affect how radon behaves indoors.
An older result can still be a useful starting point. For a sale, though, a current test taken under consistent conditions gives a clearer picture.
If the result is high
EPA recommends fixing a home if the level is 4 pCi/L or higher, and says owners should consider fixing it between 2 and 4 pCi/L. A high result is a problem with a known solution. Buyers and sellers can talk with their agents about how to handle it under the sale contract, and a radon professional can look at the home and give a quote.
The usual reduction method is active soil depressurization. A vent pipe and fan draw radon from beneath the foundation and release it above the roof line. Homes with crawl spaces are usually handled by covering the ground with a plastic membrane and venting from beneath it. EPA does not recommend sealing cracks alone, because sealing works as part of a system. Cost depends on the foundation type, size and layout of the home.
After a system is installed, EPA recommends retesting to confirm it is working. Many systems also have a simple pressure gauge that shows the fan is running. Retesting every two years or so, and after major renovations, is also recommended.
Choosing a qualified professional
Arizona does not run a state radon certification program. EPA recommends hiring a nationally certified radon professional, through either the National Radon Proficiency Program or the National Radon Safety Board. Help is available in Prescott, Prescott Valley, Chino Valley, Dewey-Humboldt and across Yavapai County. To be connected with a local professional, call (928) 582-8914.