Radon and Real Estate

Buying a Home with Radon

You’ve found the home of your dreams, but the inspector comes back with a report saying your radon levels are elevated.  What do you do?
Don’t worry!  A home with high radon levels can be fixed at an affordable price.  Here are some radon home buying “dos and don’ts”


DO NOT: Let elevated radon levels stop you from buying a home.

Radon problems are very common across the US.  The average radon system is cheaper to fix than: mold problems, asbestos, drug residue, a broken furnace, a new roof, a broken A/C, and the list goes on…  Radon mitigation is cheap and easy, just make sure you find a contractor that does it correctly!  Radon systems can often increase the value of your home, as they show the buyer you’ve tested.

DO: negotiate a credit for a radon mitigation system to be installed.

In Colorado, the average cost of a radon mitigation system is $1,200.  Just like with a broken window or home appliance, you can use this problem as a bargaining chip.  It is not an insurmountable problem.  Radon is commonplace and so are the qualified professionals that can help you.

DO NOT: let the seller put in the radon mitigation system.

Time and time again, we get calls from homeowners with radon systems that are not working.  Typically, they were put in by the seller when they purchased the home.  After move-in savvy homeowners performed a radon test but found their levels were still elevated–what happened?  If you found out your home had mold, asbestos, or meth residue, would you be comfortable letting the seller contract the job out to the lowest bidder??  No!  So why should you let them handle mitigating a deadly carcinogen?  Simply ask for a credit or have funds put into an escrow account.  Your realtor should have plenty of experience negotiating these types of things.  If they waiver, find yourself a new realtor.

DO: build a radon-ready home.

When building a new home, there is no reliable way to know whether or not you’ll have high radon levels.  There are just too many airflow dynamics at play.  If you know there is radon in your area (remember, it’s found in all 50 states), simply plan ahead and build radon ready.  Radon-ready homes have all the system components “pre-plumbed”, which allows for a quieter, less energy intensive radon fan to be installed should high levels be found.  Oftentimes, these systems cost half as much as post construction systems–and they’re totally hidden!  Other benefits include soil vapor mitigation.  Drier soils have many added benefits, ask any soils engineer!  When it comes to new construction, it just pays to build radon-ready!

DO: inspect existing systems.

As we know from www.RadonReality.com, existing radon systems do not always function properly.  If a home already has a radon system, do not assume that it has low levels.  First perform a radon test.  After that, take a look at the red flags below.  If any are present, you should call a licensed mitigator for a system servicing.

DO: perform another radon test

The EPA recommends performing a radon test every two years, regardless of whether or not you have a system.  Using an inexpensive charcoal canister, you can test your own home and know for a fact that your family is safe.  If you have a consumer-grade continuous radon monitor, please perform a self calibration every two years.  These radon monitors are a tremendous advancement in tech and they work great; however they do not tell you when they stop working!  They are not lifetime monitors.  Consumer grade radon monitors are too expensive to re-calibrate, so manufacturers advise the consumer to buy a new one once the calibration wears off.  Don’t be satisfied with results that could be false positives, self test your devices every two years with a NRPP certified short term test.






Walk around your home and take a look at your radon system.  If you see any of these red flags, there’s a good chance your system does not work.  Have a licensed radon mitigator come out and inspect the system for damage or repair.  See below for the most common red flags.


U Tube Manometer at Zero

Manometers measure the pressure in your radon system.  Typically they look like this.

This is called a u-tube and it is the most commonly installed manometer.  It is normally found inside the home on the radon pipe.  It has a scale from 0 to 4.5.  It is read as “inches of water column pressure.”  The only “bad” U tube reading is ZERO (or an even reading across both columns).  Zero means your fan is off or unplugged.  It means you have as high or higher radon levels than if you had no system at all!  It could be as simple as buying a new fan, or there could be some other red flags to check on.  All you need to know is: zero DOES NOT mean zero radon, quite the opposite.  If you can’t read the U tube, call PDS and we’ll help you through it.  Radon fans have an average lifespan of eight years.  The most common technical calls we get are about U tube readings and dead fans.  There are many, many radon systems out there with dead fans and homeowners that don’t know it.  Check your U tube (video here); test your home!!!  Watch our one minute install video at the bottom of this page.

“U bends” or right angle exhausts

Radon systems should exhaust above the eve of the roof and straight up in the air (according to most standards).  Unlicensed installers are afraid of rain.  They believe that radon systems will fill with rain water and flood basements if they exhaust straight up in the air.  This couldn’t be further from the truth.  A typical radon fan moves anywhere from 50 to 300 cubic feet of air per minute from under your soil out above your roof.  A cubic foot of air is about the size of a basketball.  Imagine 50 basketballs firing out your roof every minute!  Not a drop of rain will make it inside your pipe!  A U bend or 90 degree bend is especially dangerous as it directs radon gas (a CLASS A carcinogen) back toward the ground and re-entry points like doors and windows.  It completely disrupts the entire purpose of the system.  A “U bend” is the biggest red flag when inspecting a radon system.

Radon fan in the crawlspace or basement

The only acceptable radon fan placements are: in the attic, outside the home, or in a garage with no occupied living space above.  If the exhaust side of a radon system is compromised in any way, not only will the system not mitigate the radon, it can actively fill your home with more radioactive gas!  This is not as far-fetched as you might think.  Imagine a fan in a crawlspace, the homeowner enters to move some Christmas decorations and unknowingly bumps the radon system, then a small leak forms and this system now leaks 5-10 cfm of radon gas into the crawlspace.  Radon is colorless and odorless.  No one will find this error until a radon test is performed.  Scenario B, the home’s foundation settles and the radon pipe slowly moves a few centimeters to the side, creating a space between the fan couplings and PVC pipe.  You have another leak that won’t be found until a radon test is performed.  For all these reasons and more, stick to the code and test your home every two years as the US EPA suggests.

Extension cord to radon fan

110V radon fans need to be hard-wired and have a dedicated shut-off switch nearby.  Class II low voltage radon fans, like the KTA 150, are excluded from this requirement in most jurisdictions.  Unlicensed installers will often cut corners, not pull electrical permits, and run long extension cords to radon fans.  This is illegal and should be reported.

Exhaust under eve or near window

Radon fans should exhaust above the eve of the roof, straight up in the air (or at a 45 degree angle as of 2019), and be at least ten feet away–and two feet above–doors or windows.  Oftentimes you will see exhausts under eves or near windows.  The moist soil air will rot your soffits (an expensive mistake) and allow the radon to re-enter through the windows.

Schedule 20 pipe

Radon systems require schedule 40 PVC pipe to be used throughout the system.  Schedule 40 is thick enough to resist cracking and leaking radon gas.  Unlicensed installers will often use schedule 20 pipe because it’s cheaper.  However, schedule 20 pipe is known to crack extremely easily, especially in cold temperatures.  You can distinguish between the two by sight.  Schedule 20 pipe yellows quickly and easily; it is about as thin as your fingernail.  While schedule 40 PVC is nearly a quarter inch thick.  It is white and resists yellowing for many, many years.

Horizontal radon fan

Radon gas is a soil gas.  Soil gases contain lots of moisture.  If a radon fan is installed horizontally, it turns into a water pump.  This voids the warranty, as the fan will typically short out in a few months.  No trained and licensed installer would ever put a fan in horizontally.

Metal or HVAC fan

Again, due to soil moisture, radon fans have very high moisture protection for their motors.  Metal fans, typically used in HVAC duct systems, do not have these protections.  These fans will typically fail within weeks or months of install and are not covered under warranty when installed on a radon system.  Some HVAC, plastic inline fans will have similar model numbers and specs as compared to radon fans, but be 50% cheaper.  The reason is: they do not have the same moisture protection.  You will see these fans fail many, many years before a comparable radon fan would.

Unsealed or loose vapor barrier in crawlspace

This is a trend homeowners and professional mitigators have alerted us too.  Some home-builders are neglecting to secure vapor barrier to foundation walls in crawlspaces.  This makes any radon-ready system useless.  Even worse, some contractors are “activating” systems with a radon fan without sealing.  Perhaps your radon levels will come down to a reasonable level, however, your energy bill will shoot through the roof!  Your radon fan will pull soil air and conditioned air from the home (at up to 500 cubic feet of air per minute—-air that you paid to heat or cool!).  Imagine running your AC all day with the windows open!  An easy way to check this is with a smoke bottle or chemical smoke and an active radon fan.  See our how to guides page for details.

No installer sticker or signature

Professionals stand by their work and put their contact information on their systems.  Fly-by-night contractors looking to make a quick buck do not.  Simple as that.