Radon Testing and Mitigation in Timnath, CO
Few towns in Larimer County have changed as fast as Timnath, which grew from 625 residents in 2010 to 6,756 in the 2020 census and sits near an estimated 12,600 in 2026. That growth shows up in the housing: Timnath is almost entirely new-build, with a young stock of homes in subdivisions like Wildwing on Timnath Reservoir, Serratoga Falls, Timnath Ranch, Trailside, and Riverbend, plus its own Costco and Walmart. New construction is exactly why radon still matters here, and it is worth understanding before you assume a recent home is in the clear.
Why a new Timnath home still needs a radon test
Radon rises out of the soil and enters through the slab, so the age of the house does not protect you from it. All of Larimer County is classified as EPA Radon Zone 1, the highest-potential category, where the predicted average indoor screening level is greater than 4.0 pCi/L. You can confirm that classification on the EPA map of radon zones. Statewide, CDPHE reports that about half of Colorado homes test above the action level, though testing is the only way to know what any single home in Timnath reads.
The EPA action level is 4.0 pCi/L, and the guidance is to fix a home at or above that number. You can read the reasoning directly from the EPA action level page. A short-term test result at or above 4.0 pCi/L is the trigger that usually leads to mitigation. Radon is the second leading cause of lung cancer in the United States after smoking, according to CDPHE, which is why the number on your test report is worth taking seriously even in a nearly new house. Our radon test results explained guide breaks down what your reading means and when it warrants action.
The passive system many Timnath homes already have
Because Timnath grew up during an era when radon-resistant building was common in Northern Colorado, many newer subdivisions here were built with a passive radon rough-in: a vent pipe that runs from beneath the slab up through the roof and relies on natural airflow. That is a head start, not a finished job. Colorado has no statewide mandate for radon-resistant construction, and radon control is an optional building-code appendix that individual jurisdictions choose to adopt, as the EPA explains for radon-resistant new construction.
If your home has that rough-in and a test comes back elevated, a licensed professional can often activate the passive system by adding an inline fan rather than building a full system from scratch. That fan-only activation commonly runs about $500 to $800, while a standard sub-slab install for most Colorado homes runs $1,000 to $2,500, with about $1,500 common. Our radon mitigation cost guide covers the full range, including crawl space work.
How NoCo Radon Pros fits in
We are a free matching service, not a contractor. NoCo Radon Pros never tests, never installs, and never holds a Colorado radon license. Colorado licenses radon measurement and mitigation professionals through the state Division of Professions and Occupations under HB21-1195, and that license belongs to the professional, not to us. You can verify any contractor’s license yourself on the DORA license lookup.
What we do is connect you with an independent, state-licensed radon professional who handles the testing and, if your result calls for it, the mitigation. If you want to see how the service is paid for, read how we make money. When you are ready, you can contact us with your address and a little about the home.
Buying, selling, or renting in Timnath
With so much of Timnath turning over in recent sales, radon comes up often at the closing table. Colorado’s disclosure law (SB23-206) requires a bold-faced radon warning and disclosure of known radon information in a residential sale under C.R.S. 38-35.7-112, and it sets written disclosure duties for landlords before a lease is signed under C.R.S. 38-12-803. Our Colorado radon disclosure law guide explains both, and the full Colorado radon law guide goes deeper on licensing and tenant rights.
Whether you are testing a brand-new Timnath Ranch build, activating a passive system in Wildwing, or sorting out a sale in Riverbend, the next step is the same: get a real test result, then work with a licensed local professional. Start by browsing our radon testing service or heading back to the locations hub to see nearby Northern Colorado towns.