Radon in your home

January 7, 2020

Many of you may not be aware, but January is Radon Awareness Month, which makes it the perfect time to try to clear up some misconceptions and shed some light on the importance of testing for radon in your home.

What is radon?

From epa.gov/radon: “Radon is a radioactive gas.  It comes from the natural decay of uranium that is found in nearly all soils. It typically moves up through the ground to the air above and into your home through cracks and other holes in the foundation. Your home traps radon inside, where it can build up. Any home may have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements.”

Radon is colorless and odorless and is the 2nd leading cause of lung cancer, second only to cigarette smoking. Radon is responsible for approximately 21,000 lung cancer deaths per year. Although smokers are more likely to develop lung cancer from exposure to radon due to the synergistic effects of smoking and radon, non-smokers are still at risk and should test their homes as well.

Where does it come from?

Radon is a naturally occurring radioactive gas that occurs as radium and uranium in the bedrock break down.

Wait – it comes from rocks? Yep! Interesting – hold on – I have granite counter tops, could that be a source of radon in my house? Yes, it can. This means we prepare meals on radioactive surfaces regularly; however, radon typically dissipates very quickly and counter tops are usually not a significant source. Visit https://www.epa.gov/radiation/granite-countertops-and-radiation to learn more.

How does radon get into my house?

There are generally two ways radon enters our home – in the air, and in the water. The gas can percolate up through the soils into our houses and/or our drinking water supply.

In The Air:

Installing a sub-slab/sub-membrane depressurization system, such as seen in this illustration, reduces indoor radon levels and can reduce moisture and other soil gases as well as improving energy-efficiency.  A builder can pre-wire an outlet in an attic (or other non-living space area) within 6 feet of the vent pipe to prepare for the possibility to someday need to add a fan but for the time being leave the system passive. A passive mitigation system consists of just a physical barrier between the soil and the foundation and a vent pipe that extends from sub-slab through the roof. It relies on the natural draft effect to draw the radon out of the home and will remove about 50% of the indoor radon. If it turns out that there are elevated levels of radon, you turn it into an active system by adding an inline fan to help “vacuum” the radon out through the vent pipe.

If you are considering building a new home, check out this publication Building Radon Out: A Step-by-Step Guide on How to Build Radon-Resistant Homes. It will provide you with great information and have you prepared to discuss options with your builder. Plan ahead to potentially save yourself a larger expense down the road!

Although NH doesn’t require builders to comply with radon-resistant new construction codes (RRNC), many builders are taking the initiative to make use of these relatively inexpensive techniques. Building a new home taking radon-resistant measures can cost a builder from less than $250 to $750, where fixing a radon issue in an existing home typically costs between $800-$2500.

We have found elevated radon levels in condominiums, mobile homes, single-family homes, homes on slab (no basement) and in houses that have mitigation systems already installed. Radon levels fluctuate throughout the seasons and can vary greatly depending on the weather.

In The Water:

Radon is also present in our ground water. There is no correlation between radon in the air and radon in the water – don’t let anyone tell you differently! If you have a private well (drilled or dug) and you have elevated radon levels, there are mitigation systems available. They are pricier than radon air mitigation systems, and generally run between $2500 and $5000. These systems typically aerate the water in an effort to cause the radon gas to rise to the top, at which point the gas is vented outside the the home. The type of system required will depend on the radon levels in your home. If your town or city supplies your water, check with your DPW to determine if radon is an element they test for, as it is not a federally-regulated concern at the time of this writing.

How do I test for radon?

Continuous Radon Monitor

There are DIY radon test kits available, however proper testing methods are typically not followed. DIY radon tests are NOT adequate for real estate transactions!

Your Radon-Certified NH Home Inspector can do the testing for you. If you are purchasing (or living in) an existing home that hasn’t been tested within the past two years, it would be an excellent idea to have a radon test done. As your friendly neighborhood home inspector, we would be happy to schedule a time to get that done for you. We use electronic, continuous radon measurement monitors (CRM’s) like those seen here. These monitors alert us to any tampering and help determine if windows and doors were opened to manipulate the test results.  They also allow us to download the results after it has been placed (for a minimum of 48 hours – longer whenever possible). It is relatively inexpensive (less than $200) and well worth the cost for your peace of mind.

“My realtor said that because the home is on a slab, I don’t need to test.” Your realtor is incorrect.

“My realtor said that there is already radon mitigation in place, so I shouldn’t bother testing.” Your realtor is incorrect.

“I don’t even know what radon is. Is that something I really need to test for? I don’t want to spend more money!” Contact us and visit our radon page to learn even more.

Time and time again I refer people to my favorite radon resource. Honestly, not a week goes by without me referring people to the www.epa.gov/radon website.




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