Unfortunately a great deal of my work is repairing behind other contractors. I have put together the following information to help you pick the right contractor.


Text Box: Having the company receptionist certified does you no good. The person at the door needs to know what is to be done and why. They must to know what is required by EPA’s guidelines.
Text Box: Make sure the person who shows up to do the work is certified
Text Box: Guidelines require the use of Schedule 40 pipe. One contractor uses Schedule 20 which can be damaged by a blow from a blunt object. Schedule 40 will stand up to a lot more than the kids can produce.
Text Box: Pipe

There are 2 major manufacturers of fans in our industry, Fan Tech and RadonAway. Both are excellent, come with a 5 year warranty you can get service under. They have an average life of about 10 years. Several local vendors are using fans designed for vending dryers and other appliances. They are metal and will not hold up to the weather.

Text Box: Fans

EPA guidelines require that the fan be located “outside conditioned space”. Conditioned space is where the heater and air conditioner control temperature. If the pipe on the discharge portion of the fan leaks it could possible pump radon laden gas back into the living space if this guideline is not observed. I have moved quite a few fans to the outside.

Text Box: Fan Location

Since the air under the slab is at about 55 degrees F and 100% humidity year round it will form condensation droplets which run back to the basement and are re-evaporated later. It the temperatures outside are below freezing, ice will form on the pipe walls. When sunlight hits the pipe chunks of ice will fall free and crash down into the fan, stopping it from rotating, ending your protection until the ice melts and the fan restarts. Along with temporarily raising the Radon level, this will shorten the life of the fan.


Manufacturers include in their paperwork with each fan recommended methods of avoiding this hazard. Condensation bypasses catch the ice, melt it, and then route the water back through a bypass drain to the pipe below the fan.


In all of the repairs I have made and systems I have looked at I have yet to find a condensation bypass installed.

Text Box: Cold Weather Protection—Condensation Bypass

If you are having basement waterproofing installed they will install a system to trap water running down the wall. This opening where the wall and floor meet will allow sub-slab air to come up into the basement increasing the risk of Radon in the home. It also makes mitigation a much more difficult proposition. Putting suction on the slab simply cause the conditions air in the home to be drawn in and discharged by the Radon fan.


The weeping wall system will have to be seal from conditioned space before the mitigation system will work effectively.

Text Box: Basement Waterproofing

There is no such thing as a “Deluxe Fan”. Fans need to be sized appropriate for each application. An oversized fan will burn more electricity than necessary while pulling heat or air conditioning through the system and out of the home. Fan sizing needs to be based on soil makeup and resulting radon reduction. Pressure testing of the floor using a digital manometer is the way to diagnose fan sizing problems. Confirm that your contractor will have access to a digital manometer if it becomes necessary.

Text Box: Fan SizinG

When there is not sump system the amount of excavation under the floor at the suction hole is critical. The rule of thumb is the more difficult to dig the more dirt that needs to be removed. As a minimum 2 five gallon pails need to be removed from any hole without a drain tile system.

Text Box: Suction Hole Excivation

Sump System:

Locating the hole in the sump cover is usually not a good idea unless there is no pump and there has been no water for at least 10 years. The suction piping in the lid will make future maintenance on the sump system difficult at best. The better idea is to drill into the concrete and hit the drain system piping at another point in the system. A collateral benefit to this technique is the ability to place of the suction pipe where it can be easily discharged to the atmosphere.


No Sump System:

The placement of the suction from under the floor in a non-sump system is the most critical decision. The contractor should be able to give you logical reasons for the placement of suction and middle of the room, convenience and esthetics are not sufficient. The goal is to reach the lowest Radon level and suction under the floor is one of the greatest determinants.

Text Box: Suction Hole Location