How to test your Florida home for Radon – FREE test kit!

Nicholas NolanHome Inspections

Do you need to hire a home inspector to find out if you house contains unsafe levels or radon? The answer is not necessarily, there are many good home testing kits available from your local hardware store or for $15-20 dollars. Radon Testing

What about a free radon test?

Free radon testing home kits can be obtained in Florida for free from the Florida Health Department here. I ordered a free radon test kit for my new construction home and here were the results. The kit took approximately 7 days to arrive via USPS. Here is what it looks like…


Can my house have Radon even if it’s new?

Without testing you cannot know. All houses have the potential to have Radon especially in areas where high concentrations have been proven. Radon can naturally occur everywhere and it’s not something that tested for with a typical home inspection.

Radon disclosure in Florida Real Estate contracts

Here is the only disclosure needed when you buy a house using the Residential Contract for Sale and Purchase…

RADON GAS: Radon is a naturally occurring radioactive gas that, when it is accumulated in a building in sufficient quantities, may present health risks to persons who are exposed to it over time. Levels of radon that exceed federal and state guidelines have been found in buildings in Florida. Additional information regarding radon and radon testing may be obtained from your county health department”.

Testing?: not required. Seller Disclosure?: Only if they know about it (they probably don’t)

Conclusion: Get your own test and take action if levels exceed safe limits.

What can be done to reduce Radon in your home?

You can take steps to reduce and control the amount of radon in your home. Testing is the only way to determine radon levels. Have your home tested by a professional.  EPA guidance suggests mitigating if levels are at or above 148 Becquerels/meter3 (4 picocuries/liter). 

The effectiveness of any one radon-reduction method will depend upon the unique characteristics of your home, the level of radon, how it is getting into your house, and how thoroughly the job is done. A single method may do the job, but sometimes a combination of several methods must be used.

Homes are generally categorized according to their foundation design: basement, slab-on-grade, or crawlspace. Some homes have more than one foundation design feature: a basement under one part of the home and a slab-on-grade or crawlspace in another area. In these situations a combination of radon-reduction techniques may be needed to reduce radon levels to below the EPA guideline.

A certified radon professional will likely perform one or more diagnostic tests to help determine the best radon-reduction system for your home. For example, your contractor may use chemical smoke to see the air flow sources and radon entry points by watching a small amount of smoke that has been placed into holes, drains, sumps or along cracks. Another type of diagnostic test is a Pressure Field Extension Test (or communication test). This test uses a vacuum cleaner (e.g., a Shopvac) to measure how easily air can move from one point to another under the foundation and estimate the number of suction points and fan size needed for an active radon-reduction system.

Sub-slab depressurization (also called active soil depressurization) is the most effective and reliable radon reduction technique. It is also the most common method used by C-NRPP certified professionals. This method involves installing a pipe through the foundation floor slab and attaching a fan that runs continuously to draw the radon gas from below the home and release it into the outdoors where it is quickly diluted. This system also reverses the air pressure difference between the house and soil, reducing the amount of radon that is drawn into the home through the foundation. One, or sometimes multiple, suction points are inserted through the floor slab into the crushed rock or soil underneath to effectively reduce the radon level in the home.

The sub-slab depressurization pipe can be vented at either the roof level or ground level of the home. The fan can be placed in the basement or an area outside of the living space such as in a garage or attic. If the fan is placed inside the living space of the home, it is usually vented sideways through the rim joist at ground level, with the fan close to the exhaust location. When the fan is placed outside of the living space (e.g. attic or garage) then it is typically vented upwards above the roof.

If the fan is placed inside the home, it is important to confirm with your contractor that it is air tight and that all pipes and plumbing joints have been sealed. Properly installed fans and pipes will not leak radon into the building.

Current field test studies of indoor mounted fans with near ground level discharges show this is an effective technique. Further field testing of this system in urban environments where houses are built in close proximity to each other is necessary. To verify continued performance of any radon-reduction system, an initial long-term measurement should be made within two years of the system activation and at two-year intervals afterwards.