Do Radon Sealers Really Work?

Keeping Radon at Low Levels Reduces Your Chances of Lung Cancer... But Trying to Seal Out Radon May Not Be Enough
By Ed Buckley

Bethlehem PA – August 21, 2006. There is an undeniable risk of getting lung cancer with exposure to radon. The higher the exposure, the more likely you are to get it. Radon is radioactive and found virtually everywhere in our environment. The concentration of this odorless, tasteless, and colorless gas is much higher indoors. Why? Because it penetrates through cracks, gaps, and even through the concrete itself. What can you do to protect you and your family? The first thing is know the concentration level of radon in your home, and the only way to know for sure is to test – more on that later.

Does Radon Sealer Really Work?Once you have determined that you have a radon problem, some people look toward sealers to help keep the radon out. The effectiveness of sealers depends on how radon is entering the building and the kind of radon sealer you plan to use. There are generally two types of radon sealers. The first is a urethane based caulk. This is typically used to fill gaps around utility penetrations or cracks in wall and floor joints. Never use silicone based caulk for this application.

The second type of radon sealer is a penetrating concrete sealer. This type of sealer penetrates into the concrete and reacts with its calcium hydroxide. The reaction creates calcium silicate hydrate. This effectively seals the concrete from water vapor and significantly slows radon that may be diffusing through the concrete walls or floors.

So what does all this mean? Can radon sealers be used to significantly lower indoor radon concentrations? US EPA says “Sealing cracks and other openings in the foundation is a basic part of most approaches to radon reduction”. However, EPA goes on further to say; “EPA does not recommend the use of sealing alone to reduce radon because, by itself, sealing has not been shown to lower radon levels significantly or consistently.”

If you have a radon problem, using only radon sealers is clearly not the answer. To be effective, radon sealers must be used in conjunction with other mitigation methods such as an active soil depressurization system (pipe and fan system). However, before you go down this path, you first need to know if you actually have a problem.

The first step – testing your home
  1. In order to know whether or not you have a problem, you need to get an accurate reading of your current radon level. Radon test kits are available from various sources, but there are many confusing choices: short term vs. long term radon tests, the question of how many test kits you need, and finally where to place them.
  2. One internet site that focuses on radon testing, features a “wizard” to help guide people through the process. The wizard has two animated characters, Rae the Radon Receptionist, and Dr. Don the Radon Professor, that lead you step-by-step through 7 questions. Based on your answers, the wizard then matches your home’s configuration to over 800 possible choices. The wizard then suggests the type, quantity, and test location(s) for your specific situation. Whatever approach you use, get your kits and follow the directions on the package.
  3. It is likely that some areas of your home have higher concentrations than others. Also, radon levels vary at different times of the year. If your test result is above the EPA action level of 4 picocuries per liter the EPA recommends having your home fixed.
In conclusion, sealing your home may reduce the health risk of radon. Before you start your project, it is smart to know your current radon level. The only way to know your level is to test. Don’t wait – test today.

Article Sponsored By: is your source for information about radon and testing. Please stay tuned for future articles on exciting topics such as Radon in Schools, Radon and Home Inspections, Radon and Real Estate transactions, Radon and Home Improvement/Additions.

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