I need some help clarifying some Radon questions I have. First of all I just watched our local TV channel talking about Janurary being “Radon Awareness Month” & they showed our State Radon guy putting up free test kits in the TV station (results on tonites 10:00 p.m. news) & I noticed he thumb tacked one on the ceiling by what appeared to be a speaker cover, it didn’t really look like a heater vent & was surely not a cold air return. I thought you were not to put them by any area that could have any kind of air movement, maybe not to much through a speaker cover ? I don’t know ??? The kits I’ve seen says “Hang at breathing level” Also monitors t least 20" above the floor.??
Also if there can be so much fluctuation in levels from one side of the room to the other, (The state guy said this too) how do you explain the integrity of the test with so much variation in recorded levels to the buyers/sellers/etc. If one side of room tests (below reccommended remediation level) 3.9 pCi/L one time & 4.2 pCi/L the next & visa versa with the other side of the room ? Or even higher that really may need remediation. I read a post on here awhile back about an inspector who had a client who was asking for a refund due to his test being high & the client had another test ran by someone else that showed normals. What gives ??? Is this why a lot of inspectors don’t bother with the possible headaches of the variations with this stuff ?? :shock:
A short term Radon test can be misleading as it requires closed house conditions for 48 hrs and stable weather conditions to have any level of confidence in the results. But the guidelines for real estate transactions call out this type of testing.
A better test would be the long term test as it gives a better measurement of the average Radon concentration over a decent period of time.
Of course no one is going to wait that long for a test result.
Here is what FL says and it follows what we were taught in Radon class:
Placement of the above radon measurement devices must follow these general guidelines.
· Measurement devices (short-term) shall be exposed or operated in place for at least 48 hours, or
longer if recommended by the device manufacturer.
· Measurement devices (long-term) shall be exposed or operated in place for at least 90 days, or
longer if recommended by the device manufacturer.
· Measurement of habitable spaces only as defined in appendix A.
· Measurement devices shall be placed away from room corners, between 2 feet and 6 feet above
the floor, at least 1 foot from any wall, and at least 3 feet from windows or other potential openings
in an exterior wall.
· Measurement devices shall be placed away from drafts caused by sources such as HVAC vents,
doors, fans, windows, and fireplaces.
· Measurement devices shall be placed in areas where they remain undisturbed.
· Measurement devices shall not be placed in direct sunlight or near or on top of appliances or other
devices which emit heat or moisture.
· Measurement devices shall be placed in areas of normal air supply and shall not be shielded or
covered during the measurement period.
· At least one measurement shall be taken for each 2,000 square feet of habitable floor space or
portion thereof in each room to be measured.
· A duplicate measurement shall be taken at 10 percent of the measurement device locations for
quality assurance.
· One additional measurement device shall be used for each 20 devices to monitor problems occurring
during shipping, storage, or processing of measurement devices. This quality assurance device
shall be opened, then immediately resealed for the remainder of the exposure period, and
processed with the other exposed measurement devices.
Thanx guys for the replies, Dick ,this was our state guy that certifies people, it blew me away when I saw it this a.m. I wish my VCR worked I’d like to get a copy of it on tape, especially if he’s wrong, that’s scary. Even on the package it says “breathing level”…
:shock: