Radon testing – Everything you need to know!

Radon testing is one of the most important steps you can take to protect the air quality inside your home or workplace. Radon is an invisible, odorless, radioactive gas that forms naturally in the ground. While it disperses harmlessly outdoors, radon can accumulate indoors and reach concentrations that increase the risk of lung cancer over time. Because radon cannot be detected by human senses, testing is the only way to know whether your building has elevated radon levels.

In this guide we explain everything you need to know about radon testing and how radon forms how it enters buildings, the different types of radon tests, what your results mean, and what to do if radon levels are high. Consider this your complete resource for understanding and managing radon safely.

What Is Radon?

Radon is a naturally occurring radioactive gas produced when uranium in soil and rock breaks down. It moves upward through the ground and can enter buildings through cracks, gaps, drains, or porous foundations. The common characteristics for radon is:

Radon gas is colourless and odourless and are also completely invisible. Radon has been proven to be a hidden health risk because of that. Long-term exposure to high radon concentrations is a leading cause of lung cancer among non-smokers. Therefore, testing is the only way to identify unsafe levels and take action.

What is Radon Testing

Radon testing is a simple way to measure how much radon gas is inside your home or building. Because you can’t see or smell radon, the only way to know if your air is safe is to test it using a small detector placed in your home for a few days or months. The detector is then analyzed by a lab to tell you whether your radon level is low, normal, or too high.

How Radon enters homes and buildings

Radon typically enters through the lowest level of a building often the basements, crawl spaces, or ground floors. Some of the common entry points include, cracks in the foundation or from floors. Sometimes it comes from walls or gaps around pipes, cables, or utility lines. The gas can also sip in through floor drains and sump pits or crawl spaces with exposed soil. Radon can also entry some construction joints, porous concrete or block walls.

Radon levels vary widely from one property to another, even among neighbouring homes. Different factors such as soil composition, ventilation, season, and building design all influence indoor concentrations. This variability makes individual testing essential.

Why Radon testing is necessary

As there are no safe way to guess radon levels, the only way is to do a Radon testing. It can confirm whether your home or workplace has elevated radon. You should test because:

• Radon is a proven health risk

Long-term exposure increases lung cancer risk — especially for smokers.

• Radon is impossible to detect without testing

You cannot see, smell, or feel radon.

• Radon varies from home to home

Two identical houses side by side can have completely different radon levels.

• Testing is quick, inexpensive, and accurate

Modern detectors provide reliable results with minimal effort.

• Many regions have regulations or guidelines

Schools, workplaces, and rented buildings must be tested regularly.

Different types of Radon tests

There are two primary categories of radon tests to be used, short-term and long-term. Each has its own advantages depending on the purpose of the test.

Short-term Radon tests

The short-term tests measure radon levels over a brief period from 2 days up to 90 days. They’re commonly used for: Real estate transactions, initial screening and quick checks before long-term tests.

Short-term tests are convenient and fast, but radon levels fluctuate daily and seasonally. As a result, these tests may not always reflect your long-term exposure accurately.

Long-term Radon tests

A long-term test measure radon for 90 days or more, often up to a full year. They provide the most accurate average radon level and also account for seasonal variations. Long term tests offer the best basis for deciding on mitigation.

For homeowners, long-term radon testing is considered the gold standard and the most reliable way to understand true exposure.

How to test for Radon (step-by-step)

Testing for radon is simple and it is easy to do it yourself. But accuracy depends on proper placement and how well you follow the procedure. Here’s how to do it:

1. Order a certified radon test kit

Choose a detector from a certified radon laboratory or a professional radon provider.Then select either: Short-term test (fast snapshot) or long-term test (most accurate).

2. Place the radon detector correctly

Place the device in a frequently used room on the lowest lived-in level of your building, for example a Bedroom, living room or office.

Spaces to avoid are bathrooms, kitchens and laundry rooms. Also avoid areas with high humidity, near vents, windows or exterior walls.

3. Leave the detector undisturbed

It is important to follow the test duration instructions carefully and do not move around the detectors during the testing period.

• Short-term: 48 hours to 1–3 weeks
• Long-term: 90+ days

Keep windows and doors closed as much as possible, especially during short-term testing.

4. Return the detector for analysis

After the test period is finished return the detectors according to instructions in the test kit.

Seal the device, send it to the laboratory and wait for your radon measurement report

5. Review your results

When you get back the lab report it will show your average radon concentration, typically measured in either:

• Bq/m³ (becquerels per cubic meter)
• pCi/L (picocuries per liter)

Then you can compare your results with your country’s recommended action levels to know if the levels are normal and your indoor air is safe.

Understanding Radon test results

Every country sets its own radon action levels, but guidance generally falls into three categories:

• Low level: No immediate action needed
• Elevated level: Consider long-term testing or mitigation
• High level: Mitigation strongly recommended

Even if your levels are below the action threshold, many experts advise reducing radon wherever possible because there is no known safe level of long-term radon exposure.

What to Do If Your Radon Levels Are High

High radon levels do not necessarily mean your building is unsafe, but action should always be taken. There are modern Mitigation systems that can reduce radon levels dramatically, up to 90%.

Common radon mitigation methods include:

1. Sub-Slab Depressurization (SSD)

The most effective method. A pipe-and-fan system draws radon from beneath the foundation and vents it outdoors.

2. Sealing cracks and openings

Helps prevent radon entry but is rarely effective alone.

3. Improving ventilation

Increases airflow and dilutes radon levels.

4. Crawl space treatments

Sealing and ventilation can help reduce radon entering from exposed soil.

After mitigation, retest your home to ensure levels are properly reduced.

How often should you test for Radon?

The recommendations are to do a re-rest in following cases

• You move into a new home
• You renovate or make structural changes
• You change your ventilation or HVAC system
• You install (or modify) a mitigation system
• It’s been several years since your last test

Radon levels can change over time due to construction, weather, or soil shifts. Regular testing ensures ongoing safety.

Radon in Schools and Workplaces

Radon isn’t just a residential issue. Schools, offices, and public facilities can also have elevated radon. Some Governments require or recommend mandatory radon testing and periodic retesting. Mitigation if radon level exceeds the limit. Because children and workers spend many hours indoors. It is critical for safety testing these buildings.

Frequently Asked Questions About Radon Testing

Is radon dangerous?

Long-term exposure increases the risk of lung cancer.

Can I detect radon without a test?

No. Radon is completely invisible and odorless.

Do new homes have radon?

Yes. Radon depends on the ground, not the age of the building.

Is mitigation expensive?

Costs vary, but mitigation is typically affordable — and highly effective.

Should I test if my neighbor has high radon?

Absolutely. Radon levels vary drastically between properties.

How much cost a radon test?

The cost of a radon test depends a lot on the method, kit type, property size, and region. Here’s a breakdown:

• DIY short-term test kits (you place & send to lab) can cost around $10–$50 USD.
• Professional testing by a certified technician in a home often runs $125–$400 USD for standard houses in the US.
• In the UK, you’ll find test packs around £50–£100 for typical residential tests.

Radon testing – the first step toward safer indoor air

Radon testing is simple, affordable, and essential for protecting your health. Since radon is impossible to detect without proper measurement, testing is the only way to know if your indoor air is safe.

Whether you’re a homeowner, a property manager, or a business owner, accurate radon testing empowers you to take control of your indoor environment. If radon levels are elevated, proven mitigation methods can significantly reduce exposure and help create a healthier building for years to come.