Radon Testing

Frequently Asked Questions About Radon Testing

When is it recommended to use multiple radon monitors during a test?

1. Each area that exceeds 2000sf on the level of the home being tested

2. Each area of the home served by a different heating and cooling system; and

3. Each unique foundation area.  This recommendation includes split-level foundations or where slab-on-grade rooms attach to basement or crawl space areas.  One test location may not be representative of radon concentrations in other areas of the home.

Who is the regulating authority for Radon Testing and Mitigation in the US?

The EPA is the regulating authority for radon testing and mitigation in the US. 
Here is a resource by the EPA:  Home Buyer’s Guide

What should I do if my radon test result is low?

Generally, a low test result is good, although the EPA does state that low radon may still pose a risk.  The EPA recommends retesting every two years.  The EPA also recommends retesting after basement renovations and additions.

When radon is still a concern, there are radon reduction strategies that the EPA recommends:

Radon reduction strategies

What should I do if my radon test is high?

The EPA recommends mitigating if the average over 48 hours is 4.0 pCi/L or higher.  Mitigation is reliable, affordable, and effective.  Typically, radon reduction systems cost less than $1800, but houses with large crawl spaces or different foundation types could cost more.  Often, the seller will pay to install a radon reduction system (but this is not always the case).  A Radon Reduction Specialist can be consulted for an estimate.

What should I do if ‘closed conditions’ were not maintained during the test?

Sometimes, we discover doors or windows have been left open during the test; in this case, retesting is recommended.  This is unfortunate as we do everything we can to inform the seller about the importance of maintaining closed conditions during the test– we leave placards in the home and email the seller’s agent an email with special instructions well before the test takes place.  The retest cost is $145 plus applicable travel fees (it costs more to do a radon test without a home inspection because an additional trip is required).  Ideally, the seller would pay for the retest as it was more than likely a failure on their side to maintain conditions, but in some cases, it comes down to the buyer to pay for the retest.  In some cases, it will be nearly impossible to maintain closed conditions during the real estate transaction. In this case, waiting until after the buyer purchases the property is recommended so that closed conditions can be reliably maintained.

Should I test for Radon if there is already a reduction system?”

The EPA recommends retesting your home every two years, even with a radon reduction system in place. If the seller cannot provide a test result within two years, ordering a radon test with your home inspection is recommended.

Generally, when installed well and working correctly, radon reduction systems reliably reduce radon to safe levels in the home.  However, there are two questions to ask with homes with mitigation systems in place (see below). A negative test result is still worth the cost of the test if it gives the buyer peace of mind.

How can we determine if the Radon Reduction System was correctly installed?

The best practice is to test for radon whether or not the home has a Radon Reduction System in place.  We have tested houses with radon reduction systems that have come back high– typically, this is because the system was not installed correctly (missing fan, the timer on the fan, etc…) or because the fan had failed or was turned off somehow – but occasionally everything appears to be working, and the result still comes back high. For years, there was this idea in our industry that ‘passive radon reduction systems’ or systems without fans would reduce radon to safe levels in the home. Still, over time, we are seeing that this is not the case– radon reduction systems need to be under negative pressure (fan-powered) to work reliably.

How can we determine if a Radon Reduction System was appropriately maintained?

These systems need maintenance and repair like anything else in the home. The components that often fail on these systems are the fan and the manometer (pressure gauge), which typically have an 8-12-year life expectancy.  Keep in mind that the manometer only indicates that the system is under pressure and does indicate the radon levels in the home. If the fan is failing or has failed, then radon levels will likely be higher in the home.

What are acceptable ways to test for radon?

According to the EPA, there are only two acceptable ways to test for radon during a real estate transaction:

• A 48-hour test with a certified and calibrated radon monitor  (these are very expensive and must be calibrated every year)
• Two 48-hour charcoal test kits with an accredited lab

There are also precise placement, documentation, and handling procedures that are best left to the professionals.  The owner/occupants need to be notified about maintaining closed conditions.  For real estate transactions, a PDF document of the results from an EPA-approved method or device is the only thing that will carry weight with the seller.

Cheaper test kits and monitors are sold at hardware stores and online, but these are rarely approved or accurate, especially when they are not placed or handled by a professional.

What if there is a radon monitor already in the home, and it indicates the levels are low?

Typically, what is seen near radon reduction systems are manometers or pressure gauges that only indicate whether the radon reduction system is under pressure.  These manometers do not provide any information about the radon levels in the home.  Sometimes, small digital devices are found in the house that pretend to monitor radon levels – the EPA does not recognize these as proper monitoring devices and typically are not accurate- these are generally considered educational or for entertainment purposes only.  Professional radon testing is best ordered with your home inspector to ensure professional and precise results that all parties trust.

How often should I retest for radon?

The EPA recommends retesting for radon every two years or after any renovations.

How is radon tested?

Builder Buddy Inspectors conduct the radon tests using the RadStar RS300 or the RadonPro Continuous Monitor devices.  These machines are placed in the lowest finished space in the home for 2-4 days — they take readings every hour and have a tamper sensor.  The RadonPro also takes humidity and temperature readings, which helps indicate whether closed conditions were maintained during the test.  One of the many advantages of continuous monitors is that they produce 48-96 readings instead of just one with the charcoal/cartridge tests.  The additional information is used to create graphs that show spike or tampering events.  Results are back within three business days.

How quickly can radon levels change in a home?

The radon levels in a home can plummet within minutes if a door or window is left open, which is why maintaining closed conditions during a test is essential.  After conditions are closed, the radon levels can take hours or a couple of days to trend back to higher levels.  Radon has a half-life of 3.8 days before it deteriorates and emits alpha particles, so even new homes can test high for radon.

Reviews for our Radon Testing