Radon testing

Set challenging conditions

  • Test during reasonably worst case conditions, such as:
  • Close windows & doors starting 12 hours before the test.
  • Test in the lowest livable level, or even in the crawl space.
  • Sample off the floor, away from windows.
  • Test during calm weather; especially avoid windy days.

Measure the concentration level

Choose the best method of analysis, for either initial screening or long-term average:

  1. Test using a continuous monitor (“RnCM”, like the Professional Continuous Radon Monitor Model #1027, by Sun Nuclear Corp.) onsite (hourly readings, onsite readout), or
  2. Test using a continuous monitor in room air collected in air bags (fill several onsite, read with monitor in lab), and/or
  3. Test short-term average using passive activated charcoal samplers (“RnAC”, like by Air Chek) (exposed a minimum of 2 days onsite, better 4 days, then mailed to their lab in North Carolina) (these are good for many locations at once), or
  4. Test long-term average using an alpha-track (“RnAT”, like by RSSI) film badge for months.
  5. Test water samples collected for lab analysis.

Test again if levels high

  • Test again in more and different locations, on upper floors also, to find the source:
    • soil gases? (the most common source)
    • interior masonry, granite, or rocks?
    • well water?
  • Test also to find the entry pathways: from the basement? (more in one end or corner?), the crawl space? the well water?
  • Use your own direct reading continuous monitor Safety Siren SM-RAD-PRO3 for $130. from Safe Home Products, Inc.

Get more info from the US EPA.

©2004-2017 Richard Knights, Blue Sky Testing Labs, Seattle, blueskylab@pobox.com