Radon in the Air – FAQ’s


STORCH Radon Services, Inc. encourages you to print this guide and add it to the important literature you are gathering as you prepare to buy or sell your home.

Question: What is Radon Gas? Answer: Radon Gas is a radioactive element which is a byproduct of the breakdown of uranium, which commonly found in rock and soil.

Question: Where should Radon Testing be conducted and at what level is it a concern? Answer: Radon Testing should be conducted in the lowest livable area of the home. This is an area that can be made livable with little modification, or where a frequent amount of time will be spent.

The Environmental Protection Agency (EPA) suggests action be taken when radon levels are 4pCi/L (Pico Curies per liter of air) or greater.

Question: What type of Radon Testing is available? Answer: There are two types of Radon Tests available…Long-Term and Short-Term:

A Long-Term test utilizing an alpha-tracking monitor is conducted for at least one month. However, it is generally conducted over the course of six to twelve months. This testing method can be desirable to average out changes in climate, which can affect the indoor radon levels. It is important to note that cold weather can be conducive in elevating radon levels.

A Short-Term test lasts for a minimum of Forty-Eight (48) Hours, though it can be conducted for as long as one week depending on the criteria set by the testing laboratory.

The two most common type Short-Term tests are an activated charcoal test and a continuous radon monitor. While the charcoal test is less expensive than a continuous radon monitor, it is more vulnerable to tampering than a radon monitor. The continuous radon monitor is more secure.

It is important to note that both tests have been found to be accurate and strive to be less than 25-percent inaccurate. Short-Term testing is more common and practical when selling or purchasing real estate due to related time constraints.

Question: What if the Radon Level is found to be 4pCi/l or greater? Answer: At the Buyer’s or Seller’s discretion, a second test may be conducted in order to make certain the results are consistent further ensuring the accuracy of the testing.

If a second test is conducted, and results in a 50% or greater differential from the radon Level of the first test, a third test may be considered.

If the two tests have a less than 50% differential, the correct procedure is to utilize the average of the two tests.

Question: How does Radon get into the home? Answer: Radon is a by-product of radium, which is commonly found in rock and soil. Radon takes the form of gas causing it to escape from the ground. The Radon sits below the basement floor. When the home is under negative air pressure, which is the flow of air from the lowest area of the home upward, the Radon enters the house.

Compare this to a leak in your car’s tire…whereas the air will only stop leaking from the tire when their is no air pressure imbalance.

By virtue of removing the Radon Gas from below the basement floor, the Radon gas leakage into the home is reduced.

Question: How do I reduce Radon Levels in my home? Answer: Corrective measures are determined by the type of basement you have. Generally there are two types of foundations, concrete, and stone/dirt. Stone/dirt foundations are most common in older homes (pre-dating 1920) while concrete basements are found in newer homes.

Question: I have a concrete basement, what is the method of mitigation? Answer: Applying a method known as sub-slab depressurization usually reduces the Radon Gas. This method is designed to reduce the Radon gas built up below the basement floor. PVC piping is inserted and sealed into the basement floor which is attached to an on-line fan creating a vacuum within the pipe which in turn suck’s the gas from below the basement floor.

Question: Where is the vent pipe installed? Answer: The PVC piping is generally vented to the roofline of the home. It must be ten (10) feet above ground level and twenty four (24) inches above the highest un-sealed window, door, or any other such opening. If the 24 inch is not met, maintaining a 10 foot clearance away from the openings to the dwelling is also acceptable.

Question: What does the installed system look like? Answer: If the PVC pipe is extended from the basement out over the top of the foundation through the side of the home (generally near the back corner board) and extended upward to the eave it will look much like a downspout.

If the home is a multi-level structure, such as a colonial home, the PVC pipe can extend from the basement into a series of closets stacked one of top of another into an accessible attic and out through the roof. It is important to note that this configuration requires that the first and second floor closets be stacked on top of one another.

If there is an attached garage the PVC pipe may be routed into the garage and exit through the garage roof. It is important to note that this configuration works best when the room above the garage is not finished.

Question: I have a stone/dirt basement, what is the method of mitigation? Answer: Because the Radon source is stone, the radon may be entering from both below the basement floor and from the foundation walls. The installation of a heat recovery ventilator is sometimes recommended. The heat recovery ventilator takes the indoor air and vents it outside while simultaneously taking the outdoor air and bringing it in. The heat, which is normally lost by virtue of uncontrolled ventilation, can be reclaimed by up to seventy (70) percent. The heat recovery ventilator generally reduces indoor radon levels overall by 50 to 75-percent.

Question: How do I know if the radon system is doing its job? Answer: STORCH Radon Services provides follow-up testing upon completion of all installations.

Question: How do I know if the radon system is doing its job in the future? Answer: STORCH Radon Services includes a lifetime written guarantee warranting the system will keep the indoor radon below the EPA action level of 4pCi/L.