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Radon Mitigation Substandard Materials and Improper Methods Result in Unsafe Systems

We take pride in Our radon systems which are installed properly, using quality materials. Our radon mitigation systems operate safely for a long service life, requiring very little maintenance.

However some radon contractors and do-it-yourself homeowners install radon mitigations systems using substandard materials and improper methods. This often leads to unsafe systems and non working systems that need repair or replacement. About one third to half of the service calls I receive to repair radon systems installed by other companies turn out to be improperly installed radon systems that used substandard materials.

Two primary reasons for using substandard materials and improper methods in radon mitigation systems:

  1. Love of Money or Greed –  A Radon contractor or homeowner, who know better, cuts corners to save time and or material costs.
  2. Ignorance – A do-it-yourself homeowner or inexperienced radon contractor who just plain does not know the proper way to do it and assume their work is good enough. There is plenty of information readily available on how to properly mitigate radon so this ignorance is akin to Laziness.

Incompetent and  unethical work in radon mitigation installations are two of the main reasons radon mitigation standards were developed. Different radon certification training programs and radon contractor licenses have been developed and are required in some states to help reduce the practice of installing improper and unsafe radon mitigation systems. At the time of this writing, there is no radon certification or radon license required to perform radon mitigation in New York State. There is very little if any regulatory oversight or code enforcement in New York State in regards to the installation of radon mitigation systems. In fact, very few code enforcement officers are even aware of what constitutes a proper radon mitigation system.

A side note, this is reason I got into the radon mitigation business. As a NY State licensed home inspector with 30 years of construction experience, I had performed over 2000 home inspections in central NY where close to 1/3 of the homes have a radon mitigation system. As I became educated as to what a proper radon mitigation system looks like, I realized there were very few systems that were properly installed according to the EPA Radon Mitigation Standards

Caveat emptor is Latin for “Let the buyer beware” – Radon contractor certifications and licensing are no guarantee for a quality or safe radon system. I have inspected or worked on over 2000 homes with radon mitigation systems and well over half of those were improperly installed using substandard thin wall schedule 20 pipe to vent the radon. Unfortunately as evidenced from the many hundreds of substandard and unsafe radon mitigation systems I’ve seen as a home inspector or that I’ve been called to repair, were installed by “certified contractors”.

I know of some certified radon contractors in central New York who most often, only use substandard, thin wall schedule 20 PVC radon pipe to vent the radon. Why would they and so many others do this? First of all it’s cheaper, about half the price, it’s one third the weight making it easier and faster to work with. Even worse in a lot of the radon mitigation installations I’ve seen that use schedule 20 drain pipe, the installers don’t even glue the pipes into the fittings! Schedule 20 PVC pipe and fittings do not fit together tightly and over time, and because these guys are in such a hurry they don’t even bother to glue the pipes together, they end up coming loose or falling apart.

This is one example of substandard materials commonly used on radon mitigation systems: Thin wall schedule 20 PVC, the radon vent pipe of choice by many radon certified contractors is less than 1/10 the strength of the schedule 40 PVC pipe that is should to be used; it is very brittle and easily cracks in below freezing weather; it turns yellow when exposed to the sun’s UV rays; it can actually deteriorate in about 20 years or less when exposed to direct sunlight. The use of substandard material is a common problem in many areas of construction, especially when competitive bidding determines who gets the job and the contractor knows they can get away with using substandard materials.

The vast majority of radon systems are installed as a contingency to sell a home, and are paid for by the home seller. In this case the home seller typically looks to hire the least expensive contractor who can get the radon reduced to an acceptable level and usually do not care about the quality of the system (they are selling the home).

In this dog eat dog world we live in, as in any business, there are those who have no qualms about cutting corners to get the job or make a bigger profit.  Cutting corners in a radon mitigation system may be; using substandard materials, improper methods, improper testing, worthless warranties or no warranty at all, or no guarantee the system will even work. Often radon systems are installed and never even tested to determine if they work or not. The new homeowner does not find out its not working until they go to sell the house some years later and another radon test is done that finds high radon. That is when I get called to come and fix the system, for lack of the installers contact information, or the installing company is no longer in business.

The EPA Radon Mitigation Standards require that radon mitigation systems be labeled with a data to include the installation date, installers name and contact phone number. It’s surprising the number of systems (easily over 100 in the past several years), that I was told were installed by a radon mitigation company, that have no contact information, no name or phone number at all. I would say close to 100% of the time when I’m called to repair an unlabeled radon mitigation system, shoddy workmanship, substandard materials and improper installation methods are present. Unlabeled radon systems are those the installers really did not want their names or phone numbers on. In most of these cases the words, fly-by-night, unreliable, unscrupulous, shoddy, untrustworthy could be used to describe a radon contractor who does not put their name and number on their finished work. Once paid, they have no intention of ever returning for any reason.

An Important Note on Radon Certifications, Licensing, and Professional Training:  It’s ironic that most of the improper radon installations I’ve observed over the years were installed by so called “Radon Certified” –  individuals or companies, which had taken the required classes and passed the exam and paid the fee to obtain their certified status. There are several different national organizations and agencies that offer “Radon Certifications.”  From what I’ve seen, radon certifications are used primarily for marketing; they certainly are not good for any type of job quality assurance that I know of.

In New York State at the time of this writing, there is no requirement for Certification or Licensing by New York State for radon mitigation.  It is reported that  the radon mitigation and testing industry is a multibillion dollar industry. The radon certification organizations may have good intentions but have no real course of action on monitoring or disciplining their certified members for non compliance to their radon mitigation certification standards. The safest bet is to do your radon homework, ask questions and know what to look for in a proper radon mitigation installation.

Following are some picture examples of improper and unsafe radon mitigation systems I have come across, from houses I’ve inspected or worked on or from examples on the web. Click on most pictures for larger viewing size.

“The exhaust fan must not be located in or below a livable area” is a quote from the EPA booklet, What to Look for in a Radon Reduction System. All radon vent pipe past or on the discharge side of the radon fan is under high positive pressure. Radon fans are powerful, typically moving 100 too 250 cubic feet of air per minute; any break in the pipe or loose fitting or at worst a disconnected vent pipe would blow out high concentrations of radon into the home. For this reason proper installation requires the radon fan to be mounted on the exterior of the home or above the living area in an attic, or in a garage with no living area above it; in which case if the radon leaked out it would dissipate into the out door air or unconditioned air space that is vented to the exterior.

The the termination of the radon vent pipe. Radon vent pipes should not terminate below operational windows where the radon could potentially get back into the house through an open window or door.

The improper installation of vent pipe. A partial trap was formed in the horizontal radon vent pipe below the fan. In radon vent pipes one must always consider where the condensation collect and drain to.

Radon Vent Pipe Water Trap   trap, that will catch and hold condensation moisture pulled from the crawl space soil. A typical radon fan can pull up to several gallons of water a day from the soil depending on how much moisture is present. Proper installation requires all radon vent pipes to be pitched so that any condensation or water drains unrestricted back to the ground.  This partial blockage is not good for the fan and restricts the air flow, reducing the efficiency of the system and could get quite nasty over time.

More Improper and Unsafe Radon Mitigation System Pictures

Click to enlarge photo

Click to enlarge photo


Water trap formed in a radon vent pipe. This section of pipe could potentially pretty much completely fill with water and block of the air flow which would render the system pretty much useless. Any plumber understands this is a big no no with drain pipes. Radon vent pipes need to follow plumbing drain pipe installation for the most part because of all the moisture that is pulled through them.






Click photo to enlarge



Fan install on an angle and radon fan in a basement. In part for the same reason above all radon fans are required by the manufactures to be installed in an upright position because when installed horizontally or on an angle as this fan, condensation will pool and become trapped, filling the bottom section of the fan housing. The fan will be spinning in water, making quite a racket and fail prematurely. It also voids the fan warranty. Secondly this fan is also installed in the basement of a home – a safety issue.





horizontal radon fan improper installation

Horizontal radon fan, improper installation, voids warranty

Fan installed horizontally  and with flex duct and inside a basement. Three major problems here:

  1. Horizontal fan installation – wrong, will trap water, prematurely wear the fan out and voids warranty.
  2. Installed in basement – wrong, potential safety hazard, especially with the flimsy materials used to install this fan.
  3. Radon fan is attached with electrical tape to the plastic flex vent! This is very wrong, a safety hazard, could easily tear or come loose. This totally improper vent material should be PVC plastic pipe attached to the fan with heavy duty rubber couplings.


Using plastic flex vent for radon vent pipe is unsafe.

Using plastic flex vent for radon vent pipe is unsafe.

Here is an example I found on the web. Plastic flex vent was used instead of rigid PVC pipe to vent the radon gas. The same defect is seen in the picture above also. This is a thin plastic with wire inside to keep it from collapsing, insulated with fiberglass and an outer layer of this Mylar type plastic. This type of duct is designed to be used primarily for bathroom ventilation fans and sometimes for HVAC heating and cooling duct runs. The EPA radon mitigation standards require that schedule 40 PVC pipe be used for radon vent pipes; that is the same rigid PVC pipe used for your plumbing drain pipes in homes. This flimsy thin plastic vent in no way compares to Schedule 40 PVC pipe as you can see. It could easily come loose, become punctured or tear, leaking out potentially very high concentrations of radon gas into the home.


Fan in basement, leaking water and radon gas

Fan in basement, leaking water and radon gas into the home.


Improperly connected radon fan. Radon fans should be attached to the PVC vent pipes with rubber couplings. Here is a radon fan at a house I inspected, where they tried to glue the fan to the pipe. This will save $15 to $20, the cost of the rubber couplings, but the fan is not properly secured. This is a safety issue, it could fall apart, it is leaking water from condensation and also leaking radon gas. Since the fan is in the basement, the radon is leaking back into the house.




improper radon vent pipe material

Schedule 20 PVC pipe vs: schedule 40 PVC pipe

Improper use of schedule 20 thin wall PVC pipe. In this picture I placed 35 pound weights on two pieces of PVC pipe to show the difference in strength of the pipes. The thinner pipe on left was flattened by the weight only, I did not push down. The thinner schedule 20 PVC pipe on the left is most commonly used for radon mitigation because it is much cheaper and easier to work with than the heavier pipe. When the thinner pipe is used anywhere other than inside wall cavities or in attics, it is an improper and unsafe installation. If it is exposed where it can be bumped into or hit it will easily crack, especially in freezing weather it is quite brittle.

If you get a radon mitigation proposal be sure ask which type of PVC pipe they will use. Most written proposals will only say “PVC pipe” and do not designate whether it’s schedule 20 or schedule 40 pipe. These guys realize they are not using the proper pipe but will usually use the proper schedule 40 type if you insist. Most guys will also try to explain that the thinner pipe is perfectly fine. Be aware there is a reason why the EPA stipulates the stronger schedule 40 pipe be used. I have seen the thinner pipe cracked, broken and falling apart, and unglued leaking fittings in very many instances. When exposed to the sun, the thinner pipe will break down and deteriorate over time from the sun’s UV rays. Also there are several types and qualities of the thinner schedule 20 drain pipes, some of which can not really be properly glued because the hubs fit so loosely (they are designed to be glued but to be slipped together for drainage of groundwater not for venting air), which makes for loose and leaky joints resulting in leaking radon gas best if not falling apart.


Improperly installed horizontal radon fan, underground

Horizontal radon fan, improper installation, underground. Click to enlarge

Mud Pit Fan Enclosure  Here we have a radon fan that was mounted underground in horizontal position. Terrible idea, most certainly an improper installation. Photo credit to another radon professionals website. Appears the box has filled with water at times, and most likely water also collects in bottom half of fan, to bathe the bearings, not good. You could not expect a fan installed like this to last long at all.





bad traps in radon vent, improper installation.

Two fans, both improperly installed with bad “U” shaped traps in vent pipes below the fans.

Double Trouble  In this photo two radon fans are installed, both have large traps formed in the vent pipes. For both fans if the trap fills with water which is quite possible over time, the level of water at the top of the trap is at least a foot above each fan. This means the trap portions of the vent pipes and in this example the fans also would be filled with water, preventing any air flow, rendering the radon system inoperative. Not good at all, not to mention they would be quite loud working more like blenders than fans. Even though the fan motor bearing are sealed, they are not designed to run under water.