How to Test For Radon

Home Radon Kit Test Instructions

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Buying a home Radon test kit is probably one of the most important things you'll do as a home owner. But, it is almost as important to know how and where to place the test kit. If you do not conduct the test properly you will not get an accurate score. Learn how to read Radon test results.

Test for Radon on the Lowest Livable Floor

The first step is to determine which floor of the home to place the test. Place the Radon test on the lowest livable floor, which is usually the basement. If there is a finished room in the basement, such as an office, family room, computer room, or work-out area; that is where you would want to place the test.

If the basement is completely unfinished when you test for Radon, then you have to consider your situation and the future. If you only use the basement for storage and spend almost no time in it and never will, then you should place the test on the first floor. (this is the case in many old homes)

However, if you do not spend time in the basement now but it is possible that it could have a finished room in the future then you should place the kit in the basement.

When someone is trained to be a Radon Test Technician, they are trained to place the Radon test in the lowest finished or "potential" finished area.

Now that you have determined which level and room to place the Radon test kit, let's focus in on exactly where to place it.

  1. Twelve hours prior to the test, all exterior windows and doors need to be closed and remain closed during the test. This is to achieve dynamic equilibrium, or in other words, to equalize the air pressures between the inside and outside of the home. If a window were to be opened for a short period of time, it could increase the vacuum in the basement and actually raise Radon levels. If the window is left open for a long time, it could dilute the Radon level, depending on how air moves through your home. Normal entry and exit from the home is permitted.
  2. You have to determine where / what floor the test will be placed. If the basement is used quite a bit or if there is a bedroom then that is the level that should be tested. If the basement is just used for storage or laundry then the first floor should be tested. If you are selling and the basement is in good shape and can be finished off or maybe the buyers are going to work out down there the basement will normally be tested. If the basement is dark and dank, and you need to crouch down to be in it, or an old basement and it really can't be finished off - then the first floor is where the test should be conducted. If the test is going to be in the basement and there is an unsealed sump pump pit, make sure you place the kit 10 or more feet from the pit. This is to make sure the test is not biased. (Remember that Radon comes up through the slab, which is about 4 inches thick. But an unsealed sump pit is an open hole, and the Radon would have nothing to fight through to get into the air. So, Radon levels will be higher right next to an open pit.) If the crock is sealed it should be ok to test closer, but I would still test away from it to be 100% sure. Its best to test on the opposite side of the basement from the pit.
  3. Place the test kit at least 20 inches from the floor.
  4. Place the test kit at least 12 inches from a wall, or three feet from the wall if there is an exterior window or door nearby.
  5. Close any air vents that would be near the tester.
  6. Turn off all air moving devices in the area of the tester during the test. This would include ceiling fans, dehumidifiers, regular fans, HEPA or any other kind of filtering device that moves air. Also, do not use any fireplaces or heating stoves during the test unless they are your main source of heat. Ceiling fans on another floor are ok to operate.
  7. Run your HVAC system as if someone is living in the home if it is vacant. Also, if there is an air-to-air exchanger, it should be left on and run normally, unless you don't use it at all or just once in awhile. If the furnace or central air is turned on, make sure they are set to "auto" mode. The fan should not run consistently, unless it is made to run continuously which means it has a variable speed fan.
  8. When you test for Radon, Do not place the test in a kitchen, bathroom or laundry room. This is because test kits are susceptible to humidity. It is ok to place it on a refrigerator if it is not in a kitchen.
  9. If you have a crawl space in addition to your basement, you should also conduct a test in the room above the crawl space.

If you are going to test for Radon, and you want to conduct a short term test I suggest the Radon test kits by Accustar Labs, which are sold online. Get their kit which contain 2 vials, which would make it a simultaneous test. This gives you a check and balance to make sure the test was accurate. If the score is above 4 Pico curies then the two vials need to be within 30% of each other to be considered accurate. If the score is below 4, then they need to be within 60% of each other to be considered accurate. When you use the kit from Accustar Labs place the vials about one foot apart. Do not place them in separate locations. If you want to test different rooms or floors, then you need to buy more than one kit.

Be sure to see How To Read Radon Test Results.

Hopefully this will help you in placing a Radon test and get an accurate reading. If you would have any questions please give us a call. I'll be happy to help. Call us at 844-569-7236 for the Milwaukee area or 866-569-7236 for the Fox Valley - Oshkosh - Green Bay and Madison areas.

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