Radon Mitigation in Colorado Mountain Homes: Planning Ahead During Construction

What Is Radon?

Radon is a naturally occurring radioactive gas that forms as uranium in soil as rock breaks down over time. Because much of Colorado’s geology contains granite and other rock formations that can produce radon, elevated levels are common throughout the state, including many mountain communities.Radon enters homes where the structure meets the ground through crawlspaces and even concrete slabs. Since it is colorless, odorless, and tasteless, the only way to know whether a home has elevated radon levels is through testing after the home is near complete.

Is Radon Common in Colorado?

Yes. Colorado consistently ranks among the states with the highest percentage of homes testing above the Environmental Protection Agency’s recommended action level of 4.0 pCi/L (picocuries per liter).

The presence of radon can vary significantly from one property to the next. Two homes built on neighboring lots may have very different test results due to differences in soil conditions, foundation design, and airflow patterns.

For this reason, we recommend that all homeowners test their homes after construction is complete and periodically throughout ownership. S&T can help with the initial testing on completion of a new build.

How Radon Mitigation Systems Work

The most common mitigation method is called active soil depressurization.

A typical system includes:

• Perforated collection piping beneath the slab or within the crawlspace under a plastic barrier
• PVC vent piping that runs vertically through an interior wall of the home.
• An inline fan that creates negative pressure beneath the slab.
• A vent termination above the roofline that safely exhausts radon gas outdoors.

When properly installed, these systems can significantly reduce radon levels inside the home.

Planning Ahead During Construction

One of the advantages of building a new home is the ability to prepare for future needs before walls are closed up.

At S&T Construction, our standard practice is to install a dedicated radon vent pipe inside an interior wall during the rough plumbing stage. This pipe extends from the crawlspace or beneath the slab and is routed through the home to the attic area. If the home sits on a concrete slab, our standard practice also includes working with a radon mitigation contractor to install the associated collection piping under the slab prior to pouring the concrete as this cannot be done retroactively.

In many cases, a home may never require an active radon mitigation system. However, if post-construction testing indicates elevated radon levels, much of the infrastructure is already in place.

This approach offers several advantages:

Cleaner Appearance

Without a pre-installed interior vent, a future mitigation contractor often has to run PVC piping on the exterior of the home. While functional, exterior piping can be visually distracting and may affect the appearance of an otherwise beautiful mountain home.

By routing the vent pipe through an interior wall during construction, the system remains largely hidden from view.

Easier Future Installation

If a mitigation fan becomes necessary, installation is typically faster and less invasive because the primary vent path has already been established.

Lower Future Costs

Planning ahead during construction can help reduce labor and modification costs if an active system is needed later.

Better Long-Term Flexibility

Homeowners gain peace of mind knowing their home

Should Every New Home Have an Active Radon System Installed?

Not necessarily.

Because radon levels vary from property to property, we typically recommend testing the completed home first. By installing the vent infrastructure during construction, homeowners have the flexibility to add a fan later if testing warrants it.

This balanced approach avoids unnecessary equipment while still preparing the home for a straightforward mitigation solution if needed.

Building Smarter in the Colorado Mountains

Mountain construction presents unique challenges and opportunities. At S&T Construction, we focus on details that improve both the performance and longevity of the homes we build.

Installing a future-ready radon vent piping during rough construction is a simple step that can save time, money, and visual impact down the road. It’s one of many ways we think ahead on behalf of our clients so they can enjoy their homes with confidence for years to come.

If you’re planning a custom home in Chaffee County or the surrounding Colorado mountain communities, we’d be happy to discuss our building practices and the proactive measures we incorporate into every project.