Serving South-Central Wisconsin
Radon Mitigation System Madison
Reduce your indoor radon gas levels with a custom designed radon mitigation system for your Madison home
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Schedule your next-day radon mitigation system assessment free of charge
Fast & professional mitigation estimates.
We specialize in radon testing & radon reduction services across Madison & Dane County Wisconsin.
Also providing related radon mitigation system services:
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Radon fan installation (passive to active system)
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Radon mitigation system repair
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Pre & post mitigation testing (real estate compliant)
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Residential and commercial radon testing
NRPP Certified
Fully Insured
Experienced, Local, and Certified Radon Mitigation Pros
Proudly serving Madison, Monona, Fitchburg, McFarland, and much of south-central WI
Why Choose PureTech?
We act quickly & provide a transparent mitigation estimate
3-5 business day mitigation install window if needed
5-year limited warranty on entire system
Post mitigation 48 hour test included
Nationally certified with NRPP in testing and mitigation
Should Madison Homeowners Consider Radon Reduction Systems?
Wisconsin, and in particular south-central Wisconsin, has a history of returning high radon gas levels from radon testing results throughout the state. Madison and Dane County are no exception.
In fact, the highest reading that PureTech has ever come across was from a Madison home in the Meadowood and Orchard Ridge neighborhood on the west side of Madison.
The initial pre-mitigation radon test results from that Madison home was ~ 144 pCi/L (picocuries per liter). The recommended action level according to EPA is above 4.0 and the WHO recommends mitigation above 2.7 pCi/L.
After a proper radon reduction system was installed, the post-mitigation radon test results came back at 0.5 pCi/L, drastically reducing the radon related health risks of the homeowner.
PureTech's highest ever pre-to-post mitigation improvement was in Madison
From the homeowner:
"The response to our request was rapid and Zach showed up on time. We had done prior testing for radon levels and they were very high. Within a week the work was done with the radon mitigation system and levels were below recommended levels. Very efficient and effective."
Janet S., Madison WI
Radon Gas Levels in Madison & Dane County
Below is a snapshot of the Dane County radon gas testing results. These images display the latest dataset averaged from 2019-2023 and is provided by the CDC, the most up to date radon testing data available for the state of Wisconsin. Also provided is a health risk equivalent for the average radon levels of Dane County.
We created a tool to get the latest radon testing data and health risks for every zip code in Wisconsin.
Enter your WI zip code below.
How Does A Radon Mitigation System Work?
At it's core, any radon reduction system will be designed to first and foremost prevent radon gas from entering the property. Two key components of any system involve an internal radon remediation or pump system (where we draw radon gas from below your property), and an external radon ventilation system designed to vent radon gas out and above your roofline.
In this example of a radon remediation system, the homeowner has a sump pump installed and we use that same sump pit to extract the radon gas from below the slab, also known as sub-slab depressurization, before it can ever enter the home.
And we install a radon ventilation system. Radon venting is achieved by drawing the gas with a fan and venting the radon gas up above your roofline where the radon gas safely dissipates into the environment.
Here's a quick overview of how to design an effective radon mitigation system for a Madison home. We'll follow this with further explanation of the techniques used.
To lower elevated radon, Madison homes typically use a radon mitigation system referred to as a sub‑slab depressurization system that pulls soil gas from under the slab or drain‑tile and vents it above the roofline.
EPA recommends fixing at 4.0 pCi/L and suggests considering mitigation between 2.0 - 4.0 pCi/L.
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Test first; confirm with a follow‑up if borderline
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Choose a system type matched to foundation: sub‑slab, drain‑tile/sump, crawlspace membrane, or block‑wall assist.
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Seal penetrations and sump lids to improve draw.
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Vent above roofline; select a continuous‑duty radon fan sized for Madison soils.
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Post‑mitigation test and re‑test every two years or after renovations.
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Typical WI install cost: low thousands, single‑day work
When to call a pro: If results are ≥4.0 pCi/L—or 2.0–3.9 pCi/L with long‑term exposure—book an NRPP contractor like PureTech Home Services for a designed system and documented post‑test.
Which Radon Reduction System Type Is Best For My Madison Home?
Radon mitigation systems are designed depending on the makeup of the home. Whether the home is multi-level, has a finished or unfinished basement, has a crawl space, has significant square footage, and more are all relevant in the design and installation of a radon mitigation system. Below we'll review several of the core techniques for radon reduction systems in the Madison area. We may rely on one or all of these techniques to remediate high radon readings.
Sub-Slab Depressurization (SSD)
Most basements in Madison and Dane County will use a method of radon reduction known as sub-slab depressurization. This technique would be what some would refer to as the gold standard in the radon abatement field.
The technique creates a controlled vacuum below the concrete slab, also referred to as a pressure field, that ventilates radon gas and pumps it safely outside of the home. This radon reduction system often involves drilling, or coring, a hole through the slab. We connect this to a radon pump fan which acts to create the vacuum and provide the radon ventilation out into external air.
Madison homes frequently have sump pits and drain-tile systems installed. These systems often help to create more effective radon abatement systems but they do require a few slight modifications and appropriate sealing.
Here's a quick radon gas and SSD explainer video from Wisconsin's Department of Health Services (DHS)
CrawlSpace Encapsulation
Crawlspace encapsulation, or crawlspace membrane sealing, is a radon mitigation technique used when a crawlspace is present. Exposed dirt below the living space provides a very limited barrier to radon gas. So the objective is to seal off the exposed ground, creating a barrier between the gas and the living space substrate, and then provide external radon ventilation from below that sealed membrane similarly to a standard SSD system.
The crawlspace encapsulation technique is not commonly deployed as part of a radon reduction system in Madison because most homes in the area do not have crawlspaces. This technique is much more common in other parts of Wisconsin, though we do occasionally encounter them in Madison.
Block-Wall Extraction
Block-wall extraction is a radon reduction technique that's sometimes needed for hollow CMU and block foundation walls. Less a standalone abatement technique, and more an add-on to an SSD radon abatement system, it provides a separate suction point from behind or within the blocks to extract radon gas and connect to the primary system.
How Effective is Radon Mitigation in Madison?
Radon mitigation system installation is an extremely effective way of dealing with elevated radon gas levels. Radon gas level improvements can be as high as 99% below what they were pre-mitigation. A well-designed system will almost always provide radon reduction below the 4.0 pCi/L action level for the EPA, though no guarantees can be made with any home.
Are radon levels in Madison worse in the winter?
Yes, radon gas levels will almost always be elevated in Madison throughout the winter months compared to warmer spring and summer months. This is primarily due to the stack effect which is the negative pressure between the inside and outside of the home that comes naturally with a wider temperature difference. So the colder it gets, the greater the stack effect. An easy way to think of this concept is to think of turning a vacuum to draw soil gas into the home.
Also, generally speaking homeowners will have their windows and doors shut in the winter. This has a two fold effect; decreasing fresh air, and also making the pressure difference worse.
An effective radon mitigation system will run throughout the year, negating much of the stack effect and resulting elevated radon gas in a home.
Can sealants or barriers alone fix a radon problem?
Not effectively. While they can help reduce air leaks, sealants alone rarely bring radon levels down to safe levels, but they are a crucial component of creating an effective radon mitigation system. A full mitigation system is usually needed for consistent results under 4.0 pCi/L.
Do I need to re-test after I have a radon mitigation system installed?
You should always have your home tested immediately following the mitigation system installation. The EPA further recommends testing a home every two years if a mitigation system has been installed.
Will elevated radon levels or a radon mitigation system affect my home's resale value?
It depends. It is quite common that a home buyer's contract will use a radon contingency requiring testing, and if elevated levels are found, a professional take radon abatement measures. Elevated levels with no mitigation system will most likely affect your home's value negatively.
Installing a radon mitigation system typically resolves this and even enhances your home's resale value, as buyers increasingly value safety improvements and peace of mind knowing radon risks have already been addressed.
Radon is a very well-known hazard among construction outfits. So much so that new construction homes very often have passive radon mitigation systems installed by default. Some of these systems need to have a radon fan installed in order to make them effective at reducing radon levels sufficiently.
How Much Does a Radon Mitigation System Cost in Madison WI?
A radon mitigation system in Madison will generally cost between $1,300 and $2,300. The total cost will depend on the system requirements mentioned above, as well as the required fan(s), amount of PVC and electrical component routing necessary, or sealing requirements.
PureTech Home Services provides transparent same or next day estimates for all of our radon mitigation assessments.