radon test

If you’re shopping for a home, your real estate agent has probably already told you how important it is to conduct a buyer’s home inspection before you close the sale. But did you know that it’s also a good idea to have a radon test conducted?

Measuring indoor radon levels will give you insight into an important aspect of a home’s air quality and let you know if your dream house has a radon problem. If it does, your agent can work to negotiate the price down to cover radon mitigation costs.

What if you already own a home but have never had radon testing performed before? It’s never too late to take care of this important health and safety precaution. It’s easy to purchase a test kit from the hardware store, but it’s even better to call a professional home inspector who is also certified to perform a radon test. 

Here’s what you need to know.

What is radon?

Radon is a colorless, odorless gas that occurs naturally in the earth. As elements like uranium and radium break down in the rock and soil beneath your house, they release radon gas.

Reminder for anyone struggling to recall high school chemistry class: uranium and radium are radioactive. The same is true for radon gas, which can cause lung cancer — in fact, radon exposure is the second leading cause of lung cancer in the United States.

Radon isn’t a problem outdoors, because it quickly dissipates into the atmosphere, leaving only miniscule amounts in the air you breathe. But if your house is tightly sealed — as many modern homes are, thanks to high-quality insulation and efficient air sealing — you could be at risk. That’s because radon can become trapped inside and build up to unsafe levels. 

Because radon is odorless and invisible, the only way to know if you have a problem is to conduct a radon test. Both the Centers for Disease Control (CDC) and the Environmental Protection Agency (EPA) recommend checking the radon level in your home for safety, even if you don’t live in an area of elevated risk

What is a radon test?

A radon test kit collects radon gas or radioactive particles so they can be measured. This sample is used to estimate the total amount of radon in your home’s air. Because radon gas rises up from the ground, your radon testing device should be placed on the lowest level of your home that is typically occupied: the first floor in most buildings, but the basement if it’s finished to provide living space.

In general, there are two different types of radon testing: active and passive. The most common passive test is a charcoal canister. These tests contain activated charcoal that absorbs radon gas and is then sent to a lab for measurement. As the name suggests, a passive test sits in your home for the collection period (typically 48 hours, but some tests last up to a week). It’s important to keep your windows closed for the duration of the test so you get an accurate result. A high radon level would be “hidden” from the test if you left the windows open, because the gas would escape and leave you with a false reading. 

Though a hardware store kit is convenient, it’s not the most accurate or complete measure of radon in your home. These kits tend to be small, and their placement can determine what type of reading you get. Hiring a professional will help ensure that you get accurate results.

An active radon testing device is a meter that remains plugged in to provide continuous monitoring of your home’s radon levels. These need to be professionally installed and are useful for understanding how your radon levels change over time. They can be used for short-term or long-term testing, allowing your inspector to tailor the tests to your needs. An active radon monitor is often part of a full radon mitigation system installed to reduce radon levels in your home. The radon detector lets you know the system is working as designed and that your home remains protected. 

When you get your radon test results, the measurement will be in picocuries (pCi/L). According to the EPA, any home with more than four picocuries of radon per liter of air should have radon mitigation performed to reduce dangerous gas levels. The World Health Organization (WHO) recommends taking action at 2.7 picocuries.

What does a radon test cost?

If you opt for a hardware store test kit, a radon test is pretty cheap: just $10 to $30 for quick results.

For more detailed and accurate results, a professional radon test is recommended. These are performed by home inspectors with special training in radon testing. They don’t have to take long, and they’re quite affordable when bundled with a standard home inspection. According to HomeAdvisor, a radon test typically adds $90 to $250 to the cost of an inspection, which is far less than the $444 average price of a stand-alone radon measurement. Costs vary depending on the radon risk level in your region and the square footage of your home.

Radon and real estate: fact vs. myth

There’s a myth out there that radon is a deal-breaker when it comes to closing on a house. The risks of living with radon are real, and you should definitely not move into a house with elevated levels due to the risk of lung cancer. But many people think a house with radon is radioactive: literally uninhabitable and figuratively untouchable — and unsellable.

This just isn’t the truth! First of all, radon is a gas, so nothing about the home’s structure is contaminated or in any way unusable. Second, a radon problem has an easy, specific solution: radon abatement.

Radon mitigation — also known as radon abatement — is a system that reduces radon levels in your home. While it’s not possible to eliminate radon entirely, a radon mitigation system helps to expel the gas from your home to keep concentrations low. Often, the system consists of a pipe that is sunk through your basement floor and into the soil beneath your house. The pipe may continue upward through your home to an exit point on the roof, or it may exit the basement and continue upwards along the outside of the house.

Attached to the pipe is an exhaust fan that draws air from under the ground, through the pipe, and out the other end. The idea is that any radon gas being released underground will be sucked out of the home through the pipe and allowed to safely dissipate in the air outdoors instead of becoming trapped in your living space.

Because radon mitigation systems require expert installation for insertion through the foundation and the walls of your home, the job costs about $800 to $1500 to complete, depending on the size of your home and the region in which you live.

The cost of radon abatement is a major reason while good real estate agents will often suggest a radon test along with a professional home inspection. If you know ahead of time that radon is an issue in a house, your broker can ask the seller to reduce the price to cover the cost of abatement. Many sellers will be willing to do this to close the sale, especially because future buyers are likely to make the same request as well. 

Note to sellers: It makes sense for you to conduct a radon test, too. Just as a pre-listing inspection can help you zero in on which fixes to invest in, so too can a radon test. If you get great results, you can advertise your low radon numbers in your listing. And if you discover that radon mitigation is in order, your agent can advise whether it makes sense in your market to invest in a radon reduction system before you put your home on the market.

Note to homeowners: If you never had a radon test when you bought your house, it’s never too late! Remember, the EPA recommends that every home be tested, since radon is a major cause of lung cancer. Knowing your radon levels will let you know if you need to look into a mitigation system for your safety.

How to find a radon testing professional

Whether you want a detailed test immediately or you need to follow up on a concerning DIY kit result, it’s not hard to find a professional home inspector to conduct radon readings in your home. Though radon testing isn’t part of the standard inspection checklist, many inspectors have additional training in radon testing to meet all of their client’s needs. This provides one-stop shopping for real estate agents and clients looking for a complete picture of a property’s pros and cons. 

Not sure where to find a home inspector? Search the HomeGauge network to find an experienced home inspector near you.