I believe that radon is a byproduct of granite decay (working from memory here), so the foundation /basement config is not an issue. That said, it is my understanding that basements do act as a catch-basin of sorts.

 

for a gas it is remarkably heavy. The other thing to test is the water if it is sourced from a well.

 

Do you have a 24/7 outside vacuum fan?

 

I believe you are correct sir!

 

I've alway wondered if they ran continuous or if they cycle on and off.

 

So far, all the one's I heard about run constantly at a very low speed and have an alarm should they fail.

 

To Zippy's point, I believe Radon test is suggested if not mandatory in NJ. The standard for a remediation was 4 pCi/L when I bought 19 years ago.

My parents sold their house in NJ when I moved. I believe their reading was in the 30 pCi/L When I moved into my house, it was 4.9 pCi/L Remediation was to connect the vent to a fan in the attic that runs 24/7. I also had to have some sheets of material installed above my french drains, and my sump pump sealed. There's a little fluid level attached to the vent stack that gives me some impression of what's going on. To be honest, it's useless to me.

I had some work done in the house a few years ago. I retested and came in at about 4.5 pCi/L. I ignored it. I figure if I ever sell, I'll let the buyer just get a credit to do the work they want to do.

 

To Zippy's point, I believe Radon test is suggested if not mandatory in NJ. The standard for a remediation was 4 pCi/L when I bought 19 years ago.

My parents sold their house in NJ when I moved. I believe their reading was in the 30 pCi/L When I moved into my house, it was 4.9 pCi/L Remediation was to connect the vent to a fan in the attic that runs 24/7. I also had to have some sheets of material installed above my french drains, and my sump pump sealed. There's a little fluid level attached to the vent stack that gives me some impression of what's going on. To be honest, it's useless to me.

I had some work done in the house a few years ago. I retested and came in at about 4.5 pCi/L. I ignored it. I figure if I ever sell, I'll let the buyer just get a credit to do the work they want to do.

 

This is a good point that I had not considered. But how about in the summer?

 

I just got back my radon test results – not good but not a big surprise. This map shows the likely high areas.
https://geopub.epa.gov/Radon/

They recommend fixing anything over 4 parts and we tested at 11 parts.

Thankfully we both stopped smoking 27 years ago. For smokers exposed to our level over a lifetime there is a 15% chance of getting lung cancer. For those who never smoked it drops to less than 2%. I'm hoping we are not too far above those odds as former smokers. We might as well get it fixed, since it would have be done to sell the house.

Our state does not have any certification or auditing of radon specialists - so as they say on the state website "buyer beware". That's nice.