AARST_Radon_Reporter_Q32025_Single

30 | SEPTEMBER 2025 MITIGATION In the world of radon mitigation, you may come across homes that are labeled “challenging” due to their size, multiple foundation zones, sub-slab material, finished spaces, or past mitigation attempts that failed to effectively lower radon levels. Often, the true challenge lies not in the home itself but in the approach taken to solve the problem. One of the most misunderstood and underutilized tools in our industry is diagnostic Pressure Field Extension (PFE) testing. At its core, PFE testing measures the extent and strength of the suction created by your mitigation system under the slab or vapor barrier. By understanding the pressure field created by your suction point(s), you can determine whether sub-slab communication is adequate and if you’re effectively creating suction below the entire footprint of the home. Without this data, every system adjustment becomes a guess. Unfortunately, many mitigators skip this step. Instead, they default to common fallback strategies, such as installing a larger fan, adding extra suction points, or even installing multiple systems. While these methods may marginally reduce radon levels, they can also lead to overdesigned, noisy, or inefficient systems that still fail to perform. And more importantly, they do not address the root issue: continued radon entry due to inadequate pressure field extension. PFE testing helps you: • Identify areas where your system is not creating suction below the slab or vapor barrier • Determine the optimal location(s) for suction points • Balance a system with multiple suction points • Choose the correct pipe size • Determine the right fan based on actual system performance needs • Avoid unnecessary guessing, trenching, stitching, or multiple systems At American Radon Mitigation, we’ve found that obtaining full PFE coverage under the home is often the key to achieving the lowest radon levels possible and addressing the so-called “houses from heck.” What might appear to be a complex mitigation challenge is often simply a matter of gathering PFE data and making targeted decisions based on it. As Josh Kerber with the Minnesota Department of Health once told me when I was stumped on a goat barn that was converted to a house, “It’s really simple, man, all you’ve got to do is make the positive PFE numbers negative.” His advice helped me zoom out and see the bigger picture. I believe our industry would benefit frombroader adoption and training around diagnostic testing, especially PFE testing. If you regularly use micromanometers and understand how to interpret the data you see, you can save time, avoid frustration, and ultimately provide safer, more reliable results for your clients. Are you tired of guessing and the poke-and-hope method? If so, Pressure Field Extension testing gives you the data you need to design systems that work the first time. Some of my favorite courses that take a deep dive into PFE testing and the proper design of mitigation systems are offered by Kansas State University, including Optimal Mitigation and Advanced Diagnostics (OMAD) and Radon West’s: Health Canada’s Sub-Slab Depressurization Design Process. The OMAD class is offered as an in- person course a few times a year. Radon West has several self-paced video courses. Both courses have helpedme design better, more efficient, and effective mitigation systems. We’ve also added a video course to our website that shows our engineering process in action, using the principles we learned from these courses and other trainers. If you want to better serve and communicate with your customers, reduce return visits, and have more confidence when bidding on projects, I encourage you and your team to start learning more about how to design your systems effectively. Diagnostic Pressure Field Extension Testing: The Key to Solving Challenging Radon Mitigation Projects By Jesse Green, American Radon Mitigation