High radon

[Keith Runquist, CMI]

Talked with a radon mitigator today about a house he was having problems getting levels down to acceptable. Started out over 850 pico curies. He's been trying for months by adding suction points, fans, etc. He now has 15 suction point and 9 fans on the house and can not get the level below 6 pico curies. He decided to to do an outdoor test and found the level to be 4.5 pico curies out doors. I'd say a 6 is pretty good. This guy has been doing radon systems for almost twenty years. There is so much negative pressure in the house from the fans that the furnace and water heater are backdrafing. Any one else found a home that just cannot get below 4 pico curies?

[Jeffrey R. Jonas]

Originally Posted by krunquist

Talked with a radon mitigator today about a house he was having problems getting levels down to acceptable. Started out over 850 pico curies. He's been trying for months by adding suction points, fans, etc. He now has 15 suction point and 9 fans on the house and can not get the level below 6 pico curies. He decided to to do an outdoor test and found the level to be 4.5 pico curies out doors. I'd say a 6 is pretty good. This guy has been doing radon systems for almost twenty years. There is so much negative pressure in the house from the fans that the furnace and water heater are backdrafing. Any one else found a home that just cannot get below 4 pico curies?

Nope, haven't run into that one, yet.

Reminds me of the movie "Poltergeist", and has me wondering what is "under" the home, geology wise. What is the reason for the severe problem, and what will the long term consequences be? Perhaps it will never achieve an acceptable level, and just needs to be torn down. How are the neighbors homes? Any issues there? Perhaps they aren't aware, and should have their homes tested.

[Gary Farnsworth]

Due to the EPA, regulations are not allowing rock quarries to expand, so they dig deeper to get rock for concrete mixes. Could be the rock in the concrete. They may have to seal the foundation and the floor so no concrete is exposed. This happened a few years ago in Philly I believe in a condo complex and the attached parking garage.

[Keith Runquist, CMI]

The neighborhood generally has high radon. Not that high, but high. Typically 50-90 pico cuires. The homes there are mostly less than 20 years old. No one is going to tear it down, it's an expensive one. I thought maybe some sort of sealant could be applied to the concrete on the inside if the basement is gutted. Interesting problem.

[Gary Farnsworth]

Here is the link

http://www.aarst.org/proceedings/200..._EMANATION.pdf

[Michael Larson]

Originally Posted by krunquist

Talked with a radon mitigator today about a house he was having problems getting levels down to acceptable. Started out over 850 pico curies. He's been trying for months by adding suction points, fans, etc. He now has 15 suction point and 9 fans on the house and can not get the level below 6 pico curies. He decided to to do an outdoor test and found the level to be 4.5 pico curies out doors. I'd say a 6 is pretty good. This guy has been doing radon systems for almost twenty years. There is so much negative pressure in the house from the fans that the furnace and water heater are backdrafing. Any one else found a home that just cannot get below 4 pico curies?

15 suction points and 9 fans? That's nuts

He's no longer depressurizing under the slab, he depressurizing the building envelope and creating a hazardous situation by back drafting the gas appliances.

I bet it is fun opening the doors to the home as well.

Something is very wrong and he may be way over his head.

[Robert A. Wilson]

If the suction points are properly sealed and the house is backdrafting then there are openings in the slab or where the slab meets the wall.

[Gary Farnsworth]

Michael, I like your quotes. How true.

Yep. Nine fans is over the top. I have never seen more than two. Perhaps his monitor needs calibration...??