How to Test for Radon at Home: Step-by-Step Guide for Beginners

1 in 15 homes in the U.S. have high radon levels, according to the American Lung Association. So, how do you know your home is safe? Since you can’t see, smell, or taste this dangerous gas, radon testing is the only way to know about radon levels at home.

If you’re confused about how to test for radon, don’t worry. We’ve got you covered with this guide on how to test for radon at home, covering the radon testing process in detail. Just read through it and by the end, you’ll have all the info you need to get started.

Why Do I Need to Test for Radon?

Learning how to test for radon is important because this invisible gas releases hazardous radioactive particles as it decays. When inhaled, these particles attack your lung cells, increasing your risk of lung cancer over the years.

The EPA estimates that this silent killer is responsible for an estimated 21,000 lung cancer deaths in the U.S. every year. In fact, in 2009, the WHO classified radon as the second-leading cause of lung cancer after smoking.

If you or anyone in your family smokes, risks increase 10 times. But risks don’t stop there. About 1 in 7 radon-related lung cancer deaths each year occur in non-smokers, according to the American Lung Association.

The worst part is that symptoms of radon exposure don’t even show up in the short-term. You only get to understand what has happened after decades or more. As one Reddit user shared, their yard contained thorium — a source of radon — and the city replaced it when they were a teen, but about ten years later, their father developed cancer.

So how do you protect your family and loved ones? Through testing.

Testing is the only way to know if your home is safe and radon-free.

When is a Home Radon Inspection Needed?

Before we go into how to test for radon, it’s important to understand when testing is needed.

Firstly, you should know that radon can be present in any home, regardless of your county or state. Levels also vary from one home to another - on the same street. So, testing for radon is always a good idea.

But according to the Centre for Disease Control (CDC), it becomes more important in these situations:

If your home has never been tested for radon
You’re planning to buy or sell a property
Before and after renovation, especially if you’ve had foundation or ventilation work done
Before converting a lower-level area like your basement into living space (like a home office or guest bedroom)
After installing a radon mitigation system to verify if it’s working

How to Test for Radon at Home: The Radon Testing Process Explained

If you’re wondering how to test for radon at home, here’s a simple and comprehensive step-by-step guide to walk you through the process:

Step 1: Understand the Different Types of Radon Testing Devices

Before you even start with how to test for radon at home, you need to first understand the different types of radon testing devices available.

There are primarily two types of radon testing devices you can use:

Passive Radon Devices

Passive devices don’t need power to operate. Common examples include charcoal canisters, alpha-track detectors, and electret ion chamber detectors.

Here’s what you need to remember about passive devices:

These devices are exposed to the air indoors and then sent to the lab for analysis.
They don’t record start and end dates. That has to be done manually.
They can only provide an average value of your indoor radon levels.

Active Radon Devices

Active radon devices need power to function. Common types of active detectors include continuous radon monitors and continuous working level monitors.

Here’s what you should note about active devices used for radon inspection at home:

They continuously monitor radon levels in the air.
Some devices can detect test interference and can offer anti-interference features to ensure more accurate readings.
May cost more than passive devices.

Step 2: Choose Between Short and Long-Term Radon Tests

Next, you need to decide how long you want the radon testing to last and how soon you need the results. Based on that, you can choose from:

Short-term testing (48 hours to 90 days)

Short-term tests are the easiest way to get a quick radon level reading for your home. They typically cost $30- $50 per test, depending on the test kit you choose (active or passive).

These tests remain in your home for 48 hours to 90 days (depending on the device) and provide a snapshot of indoor radon levels. However, they don’t tell you anything about the year-round exposure levels.

Long-term testing (more than 90 days)

If you choose a long-term radon kit for your home inspection, you need to keep it for more than 90 days. Most homeowners keep the test year-round to detect radon level variations with the seasons and weather changes.

The good thing about these tests is that they tell you about the year-round average of radon levels at home. So, the longer the test, the more accurate the results.

Step 3: Pick Between DIY Radon Test Kit Vs. Professional Testing

This is an important step in the radon testing process because the accuracy of your results (and how you complete the next steps) depends on it.

DIY radon test kits: These are available at your nearest hardware store, or you can get one from your state radon office. You will find complete instructions on how to use them listed on the kit itself. If you’re looking for a low-cost way to detect radon at home, DIY kits may be a good option.
Professional radon testing: With professional radon testing, you’ll have certified technicians coming in with high-level equipment to detect radon. They will follow strict EPA guidelines to test your home and give you verified results.

Professional testing typically costs between $1,000 and $1,500, depending on the size of your home, and provides more accurate results. That’s why the CDC recommends having a professional radon test the property if you are buying or selling it.

Call InHaus Lab and we’ll get you a quote in 30 minutes!

Method	Pros	Cons
DIY Test Kit	Low cost (usually $30–$50) Easy to use at home Quick initial results	Less accurate Can be affected by placement or user error Not ideal for long-term measurement
Professional Testing	Highly accurate and reliable Uses professional-grade equipment Minimal chance of error	Higher cost ($1,000–$1,500 depending on home size)

Step 4: Decide Where to Place the Radon Test

So, you’ve selected an appropriate radon testing method, but where do you place the kit? The EPA recommends placing the device at the lowest level of your home, where people spend time regularly. So, like a family room or bedroom.

Here’s a simple cheat sheet according to the EPA’s Home Buyer’s and Seller’s Guide to make things easier for you:

Dos	Don’ts
Place the radon testing device where it will not be disturbed	Place the device where it’s in contact with the floor, ceiling, or exterior wall
Place it at least 3 feet from the doors and windows and 1 foot from exterior walls	Placing it in areas where objects are within 4 inches horizontally or directly overhead.
Place the device at least 20 inches to 6 feet from the floor	Place it in an enclosed space like the closet
Place it in an area that’s occupied for 4 hours or more daily	Place it in high-humidity and heat areas like the kitchen or bathroom
Place it on a flat surface, such as a desk, table, or shelf	Test in crawlspaces, wall cracks, or directly next to a sump pump, as this may give you a false reading
If using a continuous digital radon monitor, place it in rooms with less than 85% humidity	Move it to a different location before testing is complete

Step 5: Send the Test Kit to the Lab

Next, leave the radon test kit in place for as long as the instructions on the DIY test kit say. Once the test is finished:

Record the stop time and date
Reseal the package
Mail it to the lab (specified on your DIY test kit) for analysis

If you’re using professional radon testing services, like the ones offered by InHaus Lab, you don’t need to worry about this. Our expert radon tester will handle this part (and every part) in accordance with industry standards to ensure accurate results and zero hassle for you.

Step 6: Interpret the Radon Test Results

If you’ve received the report back from the lab, you might be wondering ‘What do these numbers mean?’ Well, things are not as difficult as they look.

So, let’s start with the basics. You’ll likely see the words ‘picocuries perliter’ or ‘pCi/L’ on the report. That’s the unit for radon measurement.

Next, see what your reading says and tally it with the EPA’s radon guidelines:

If levels are 4 pCi/L or higher: Fix your home immediately
If levels are between 2 pCi/L and 4 pCi/L: Think about fixing your home

You should also understand that the EPA says any radon exposure has risks and no level of radon exposure is ‘safe’. So, radon mitigation steps to reduce your exposure are non-negotiable.

Step 7: Take Steps for Radon Mitigation

So, let’s say, you find out that your indoor radon levels are above 4 pCi/L. What do you do next? Firstly, don’t panic. High levels of radon are quite common if you live in a high radon zone like Colorado or Minnesota.

But steps for radon mitigation are pretty straightforward. The EPA recommends contacting a radon expert to install a radon mitigation system at your home if levels are 4 pCi/L or higher.

Here’s what they’ll help you do:

Seal cracks and openings in the foundation to minimize radon entry.
Install a radon mitigation system with vent pipes that draw radon from beneath your home and vent it safely outside.
Add an exhaust fan to improve airflow and increase the system’s effectiveness.
Test your home again after implementing these radon mitigation steps.

Why Should You Hire a Professional Radon Testing Service?

If you’re still on the fence about DIY radon test kits vs. professional testing, this next part might help. Here’s why choosing a professional might be better:

They can evaluate your home and recommend the right testing approach
They can explain how you can maintain proper conditions during the radon testing process
They can ensure there is no interference or disturbance of the test
They can analyze the data as per the EPA guidelines
They can provide you with an independent report and explain the next radon mitigation steps

Worried about radon exposure in your home? Contact InHaus Lab for comprehensive testing today.

Want to Simplify the Radon Testing Process? Contact InHaus Lab

Don’t want to deal with the hassle of guessing where to place your DIY kit, mailing samples, and interpreting results on your own? Leave it all to the professionals. While it’s always good to know how to test for radon, the results may just be more accurate if the professionals handle it.

If you’re in Aspen or Minneapolis, just give InHaus Lab a call, and we’ll jump right into action.

How to Test for Radon at Home FAQs

1. What is radon?

Radon is a naturally occurring colorless, odorless radioactive gas that’s formed when uranium decays naturally.

2. How can radon enter your home?

Radon can enter your home through:

Cracks in the foundation
Construction joints
Cracks in the floor or walls
Gaps in service pipes
Sump hole

3. Who should be worried about radon?

Every home should be tested for radon. Radon levels can vary from one home to the next, even within the same street, due to differences in building materials, soil composition, etc. EPA recommends testing for radon in all homes below the 3rd floor level.

Even homes in states that fall within the low radon potential zone on the EPA map may have high radon levels. That’s why testing is important.

4. How can radon be detected in 2026?

Radon is a colorless and odorless gas. This means it can only be detected through testing.

5. How can I test for radon at home in 2026?

You can test for radon at home with DIY radon test kits or by hiring a professional. You can choose from short-term tests (48 hours to 90 days) and long-term tests (more than 90 days). These test samples need to be mailed to the lab for analysis.

Alternatively, you can hire a professional radon testing service like InHaus Lab. In this case, certified professionals will test your home, analyze the results, and explain the results, along with radon mitigation steps.

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