Radon Gas

Very interesting read about Radon Gas.


Have read it sir.

I have a tester that is great. I placed it in two houses in Creemore that showed high levels. After getting a source of fresh air into both houses. the picocuries dropped off the map.
I have found that unless it is a known problem area, that most radon can be controlled with good ventilation. If you have a vacummed house this will help pull the gas into a house. If it pressurized, this will help eliminate the possibility.

That is how we mitigate commercial buildings and schools.

1st thing we look for is a disconnected economizer damper. Many maintenance personal do not understand the economizer and cut the wires and prop the damper open or closed. Thus the negative building pressures.

What tester is that?

With the damper propped open, the building should be slightly pressurized.

Why is it maintenance personel are rarely trained in the basic theory and operation of the building systems? Found a lot of this when I managed an IAQ and air balancing company from 1990-1992.

That is what NACHI is all about getting information out to the NACHI members and other home inspectors who come here to learn and help spred more ideas and information .
Please as a guest try and not show up the newer inspectors .
We all wish to learn and help all.
The industry is so fortunate to have the NACHI BB No other association gives so much to so many for no charge too.
… Cookie



I leave it in a house two to three weeks and check on it when I am in the area. Leave it in a corner that is not disturbed.
I usually charge $200 - $250 to do the testing.

In my experiences as a chief engineer for some bigger highrise hotels, I will agree with that statement to a point. Very often, it is a lack of funds in the budget that allow proper repairs to the air handlers, as well as inexperienced personnel. A building is required to have a minimum damper setting of 20% open for fresh make up air, regardless of temperatures. But with the push to conserve energy and provide better performance, the damper settings are over-rode to close them tighter, or disconnected because the actuators no longer work.
I’m not saying this is acceptable, just what sometimes happens.

Has this become a requirement of codes in your area or just an accepted recommendation from ASHRAE 62, the air quality document? Mechanical designers use this document as their guideline for good practice but in codes I have not seen it made mandatory yet.