Radon Installation: What Homeowners Need to Know
When a home tests above the action level, the fix is a radon installation — the process of putting in a mitigation system that pulls radon from beneath the foundation and vents it safely outdoors. Homeowners considering one usually want to know what the work involves, how long it takes, what it costs, and what to expect once it is running. This guide walks through the installation step by step, the components involved, the timeline, cost factors, and post-installation testing. It summarizes EPA and Colorado state guidance current as of 2026 and is educational only — consult a certified radon professional for your specific home and your physician for any health concerns.
What does a radon installation involve?
A radon installation most commonly means installing an active sub-slab depressurization (ASD) system: a sealed pipe routed from beneath the concrete slab up through the home (or along the exterior) to a fan that exhausts radon above the roofline. The fan creates a slight vacuum under the slab, so radon-laden soil gas is drawn into the pipe and vented outside instead of seeping into living space. The EPA identifies ASD as the most common and reliable mitigation method, and a well-designed system routinely brings levels below the 4.0 pCi/L action level.
The specifics depend on the foundation — slab, basement, or crawl space — but the goal is constant: intercept soil gas before it enters the home and discharge it safely. The broader context lives in the radon testing guide, and a parts-level view is in the radon mitigation system diagram guide.
Step-by-step: how a system is installed
1. Diagnostic and planning
A certified installer evaluates the foundation, locates a suction point, and performs a sub-slab communication test to confirm air can move under the slab. This determines how many suction points are needed and where the pipe and fan will go.
2. Creating the suction point
The installer cores a hole through the slab (often in a basement floor or utility area) and removes some sub-slab material to create a small pit that lets the fan draw from a wider area. In crawl spaces, a sealed membrane is laid down and the pipe draws from beneath it.
3. Routing the vent pipe
PVC pipe is run from the suction point up through the home to above the roof, or up an exterior wall and above the eave. The route is chosen to be effective and as unobtrusive as practical. Joints are sealed airtight.
4. Installing the fan
A radon fan is installed in an unconditioned space — the attic, garage, or outside — never in or below living space, so any leak vents outward. The fan runs continuously and is sized to the home’s needs.
5. Sealing and finishing
The installer seals slab cracks, the sump pit (if present), and other openings to improve performance, then adds a system monitor (a manometer) on the pipe so the homeowner can see at a glance that the fan is working. The full sequence is detailed in the how to install a radon mitigation system guide.
System components
A standard ASD installation includes a few key parts: the suction point and sub-slab pit; the PVC vent pipe; the radon fan (the only powered component, drawing modest electricity); a vent termination above the roofline that meets clearance requirements from windows and openings; a manometer or system monitor showing the pressure differential; and sealant at slab penetrations and the sump. Some systems incorporate the home’s sump pump with a sealed lid as the suction point. Understanding what the finished system looks like is covered in what does a radon mitigation system look like.
Interior vs exterior routing
One early design decision shapes both the look and the cost of an installation: whether the vent pipe runs inside the home or up an exterior wall. Each approach has trade-offs.
Interior routing takes the pipe up through the house — often through a closet, mechanical chase, or the garage — into the attic, where the fan sits, and out through the roof. This keeps the fan and most of the pipe out of view and protected from weather, and the roof termination is unobtrusive. It usually requires more careful routing through finished space and penetrating the roof.
Exterior routing runs the pipe out through the rim joist near the floor and up the outside wall, with the fan mounted outdoors and the pipe terminating above the eave. This is often simpler and cheaper to install, especially in finished homes where interior routing is awkward, but the pipe and fan are visible on the exterior, which some homeowners dislike. In cold Front Range winters, condensation management is a consideration for exterior runs.
A good installer recommends the route based on the home’s layout, the foundation, and the homeowner’s preferences. Either approach can achieve the same radon reduction when designed and installed correctly; the choice is largely about aesthetics, cost, and practicality. The finished appearance of both is shown in the guide on what a radon mitigation system looks like.
Timeline and cost
A typical residential radon installation is completed in a single day — often in a few hours for a straightforward basement or slab home. More complex homes (multiple foundation types, long pipe runs, finished spaces requiring careful routing) take longer or may need more than one suction point.
Cost for a standard residential system commonly falls in the range of roughly $800 to $2,500, depending on foundation type, pipe routing complexity, the number of suction points, fan selection, and regional labor rates. Crawl-space systems and homes needing multiple points sit at the higher end. Front Range pricing reflects the region’s high demand for radon work. Detailed figures are in the radon mitigation system price guide and the cost for radon mitigation guide.
Passive vs active systems and why fans matter
Radon installations come in two broad forms, and the difference shapes how reliably they reduce levels. A passive system relies on the natural stack effect — warm air rising in the home creates a slight draw up the vent pipe — with no fan. Passive systems, often roughed in during new construction, are cheaper and silent but far less consistent, and they frequently fail to reduce elevated levels on their own.
An active system adds a continuously running fan that creates a reliable vacuum under the slab, which is why active sub-slab depressurization is the standard for actually lowering radon. Most installations on existing homes are active for this reason. A passive system that does not achieve adequate reduction can usually be upgraded to active by adding a fan, which is one advantage of building in passive piping during construction.
The fan is the component that makes an active system work, so its selection and placement matter. It must be sized to the home’s sub-slab conditions and installed in an unconditioned space so any leak vents outward. The constant suction is what intercepts soil gas before it enters living space, and it is why the manometer reading — confirming the fan is pulling — is the key indicator that the system is doing its job. The difference between system types is explored in the active radon mitigation system guide.
What to expect after installation
Once the fan is on, the system works immediately, but verification matters. A post-installation radon test — typically 24 hours to a few days after the system has run — confirms levels dropped below the action level. A properly designed system commonly reduces radon well under 4.0 pCi/L, often below 2.
The fan runs continuously and uses a modest amount of electricity; it is designed for long service and typically lasts many years before needing replacement. The manometer should be checked periodically — if the fluid levels in its two columns equalize, the fan has stopped and needs attention. Homeowners should re-test every couple of years and after major foundation or HVAC changes to confirm continued performance. Evidence that these systems work is summarized in do radon mitigation systems work, and Colorado’s high-radon context is documented by the Colorado Department of Public Health and Environment.
Maintenance and long-term operation
A radon system is largely set-and-forget, but a few maintenance habits keep it working over its life. The most important is checking the manometer — the U-shaped gauge on the vent pipe — periodically. In normal operation, the liquid sits at different heights in its two columns, showing the fan is creating suction. If the two columns equalize, the fan has likely failed or the pipe is blocked, and the system needs attention.
Radon fans are designed for continuous operation and commonly last many years, often a decade or more, before wearing out. When a fan fails, it is replaced with a comparable unit; the rest of the system typically remains in place. The fan should never be switched off to save electricity, since the system only protects the home while it runs. Its electricity use is modest and is a reasonable trade for the health benefit.
Homeowners should re-test radon every couple of years to confirm the system still holds levels below the action level, and after any significant change to the home — finishing a basement, foundation work, or a new HVAC system — since these can alter how soil gas enters and moves. Keeping the original installation paperwork and post-mitigation test on file helps with future service and with disclosure at resale. The evidence that well-maintained systems keep levels down is covered in the guide on whether radon mitigation systems work.
Installation by foundation type
The home’s foundation shapes how a radon system is installed, and most homes fall into one of three categories. A basement or slab-on-grade home is the most straightforward: the suction point is cored through the concrete floor, a pit is created beneath, and the pipe is routed up and out. Most single-day installs are these.
A crawl space requires a different approach called sub-membrane depressurization. The installer lays a sealed plastic membrane over the crawl-space floor and draws suction from beneath it, so radon is captured before it enters the home above. This is more labor-intensive than a slab install and sits at the higher end of cost. The approach is detailed in the guide on a radon mitigation system for a crawl space.
Many Front Range homes have combination foundations — a basement under part of the house and a crawl space or slab under another — which can require multiple suction points or a system that addresses each foundation section. These take longer to design and install and cost more than a single-foundation home. A competent installer assesses the foundation, performs sub-slab diagnostics where needed, and designs the system accordingly rather than applying a one-size template. Because foundation type drives both the method and the price, it is one of the first things a homeowner should expect the installer to evaluate, and it explains much of the variation in quotes across otherwise similar homes. The broader testing-to-mitigation path is covered across the radon testing resources.
When to call a professional
Radon installation is best handled by a certified radon mitigation professional, because correct suction-point placement, fan sizing, vent clearances, and sealing determine whether the system actually works. While some experienced homeowners attempt installations, the diagnostics and code clearances favor a professional, especially in high-radon regions. Front Range homeowners whose homes test at or above 4.0 pCi/L should obtain a designed quote, confirm the installer is certified, and require a post-installation test to verify the result.
References
- Consumer’s Guide to Radon Reduction — U.S. Environmental Protection Agency
- Radon in Colorado — Colorado Department of Public Health and Environment
- Radon and Lung Health — American Lung Association
If your Front Range home tested high for radon and you want a system installed correctly, you can get in touch through our contact page to connect with a certified local radon professional.