Should I order a Radon Test?

Radon testing is highly recommended in regions that have naturally occurring Uranium in the ground.  See the EPA Map of Radon Zones here.  Radon testing is recommended for all houses in all areas of Western North Carolina regardless of foundation type.  Homes on slabs and basements tend to have higher radon test results than crawl spaces but homes with all foundation types can test high for radon.

How Common are Homes with High Radon Levels in our area?

Most home buyers order a radon test with their home inspection and about 1 out of 6 homes that we see test high for radon (fail).

Does Radon Mitigation work?  How much does Radon Mitigation cost? 

If the levels of radon are high during a real estate test typically the seller pays for mitigation (but not always).  Radon reduction systems typically costs less than $1700 in our area and are generally very effective in reducing radon levels.

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 readings of humidity and temperature which helps indicate whether closed conditions were maintained during the test.  One of the many advantages of the continuous monitors is that they produce 48-96 readings instead of just one with the charcoal/cartridge tests.  The additional information is used to produce graphs that show spike or tampering events.  Results are back within 3 business days.

How long can it take to effect the levels of radon in the home?

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

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 The EPA recommends retesting every 2 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 mitigation costs less than $1800 but houses with large crawl spaces or different foundation types could cost more.  Often times the seller will pay for mitigation (but this is not always the case).  A radon mitigation 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, and in this case it is recommended to retest.  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 cost of the retest 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 it is recommended to wait until after the buyer purchases the property so that closed conditions can be reliably maintained.

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

The EPA recommends retesting your home, even with a radon reduction system in place, every 2 years. If the seller cannot provide a test result within 2 years it is recommended to order a radon test with your home inspection.

Generally radon reduction systems, when they are installed well and are working properly, 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.

Was it installed properly?

We have tested homes with radon reduction systems that have come back high– typically this is because the system was not installed correctly (missing fan, timer on fan, etc…) or because the fan had failed or was turned off somehow. 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 but 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.

Was it maintained properly?

These systems need maintenance and repair like any thing else in the home. The components that fail most often on these systems is 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 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 very specific 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 a 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 or not.  These manometers do not provide any information about the radon levels in the home.  Sometimes small digital devices are found in the home that pretend to monitor radon levels – these are not recognized by the EPA 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 accurate results that is trusted by all parties.

continuous radon monitor
Radstar 300 Continuous Monitor for Radon Testing
low radon test result
icon of certified radon inspector
We are certified radon testers