Radon Mitigation: What to Expect Start to Finish

How does radon mitigation work?

Radon mitigation pulls soil gas from under your home and vents it safely above the roofline. The most common method, active soil depressurization, uses a fan and PVC pipe to create a vacuum under the slab, so radon never enters your living space.

Radon is a radioactive gas that seeps up from the soil, and it can enter a house through cracks in the slab, gaps around pipes, or sump pits. In Madison County, the ground has enough uranium to produce radon at levels the state flags as high potential, and the Alabama Department of Public Health lists our county among 15 with the highest radon potential in the state. (alabamapublichealth.gov) That is why a mitigation system is not a luxury here; it is a fix for a measurable problem.

The core of the system is a fan that runs continuously. We install a PVC pipe that goes from a suction point in your slab, up through the house or along the exterior, and out above the roofline. The fan pulls air from under the slab and exhausts it outdoors, where it dilutes quickly. The result is a pressure difference that keeps soil gas from being drawn into your home. For most slab-on-grade houses, this is the standard and most effective approach.

We also seal the obvious entry points: cracks in the floor, gaps around utility lines, and the top of a sump pit if you have one. Sealing alone does not fix a radon problem, but it helps the fan work more efficiently. Think of it this way: the fan is the engine, and sealing is the weather stripping. Together, they cut off the pathway.

A typical system runs about $800 to $1,500 installed for a standard slab-on-grade home in Huntsville, and more complex homes can reach $2,500 or more. (huntsvilleradonpros.com) (angi.com) That price includes the fan, pipe, labor, and a post-installation test to confirm the system works. It is a one-time cost for a permanent fix.

The EPA and the U.S. Surgeon General recommend fixing any home that tests at or above 4.0 pCi/L. (alabamapublichealth.gov) Indoor radon averages about 1.3 pCi/L nationally, and outdoor air is about 0.4 pCi/L, so a reading several times higher is a clear signal to act. (alabamapublichealth.gov) If your test came back above 4, you are in the zone where mitigation is the right call.

• Active soil depressurization is the most common and reliable method.
• A fan runs continuously to vent soil gas above the roofline.
• Sealing cracks and gaps helps the fan work more efficiently.
• Post-installation testing confirms the system is working.

What to expect, start to finish

The process starts with a free on-site visit and ends with a post-mitigation test. In between, our crew installs the system, seals entry points, and makes sure the fan is running right. Here is the full rundown.

First, we come to your house and take a look at the foundation. We check the slab type, look for cracks, and find the best spot to place the suction point. We also look at your attic and roofline to plan where the pipe will exit. We bring a radon monitor and run a short test to see the current level, though we rely on your long-term test result for the official number.

Then we give you a straight quote. For a standard slab-on-grade home in Huntsville, that is $800 to $1,500 installed. (huntsvilleradonpros.com) If your house sits on a crawl space, has a complex layout, or needs extra pipe runs, the price lands toward the upper end. We tell you the exact number before we start, and we do not tack on surprise charges.

On install day, we start by cutting a hole in the slab, usually in a closet, garage, or utility room. We dig out a small pit below the slab to create an air pocket. Then we set the pipe into that hole and seal it with a high-quality urethane caulk. The pipe runs up to the attic and out through the roof, or along the exterior wall if that works better. We use a fan rated for radon service, and we wire it to a dedicated circuit or plug it into an outlet, depending on your setup.

We also seal cracks in the floor and gaps around pipes and wires. This is a detail some outfits leave out, but it matters. If the fan has to pull through every little crack, it works harder and may not create enough vacuum. Sealing is cheap insurance that the system performs as designed.

Once the pipe and fan are in, we turn it on and check the manometer, a small gauge that shows the vacuum pressure. A reading in the normal range means the fan is pulling properly. We label the system and leave you a copy of the warranty and the fan's manual.

The last step is a post-mitigation test. We run a short-term test, usually 48 hours, to confirm radon levels have dropped. The EPA action level is 4.0 pCi/L, and a good system should get you well below that, often under 1.0. (alabamapublichealth.gov) We do not leave until the numbers look right.

1. Free on-site visit.We inspect the foundation, plan the pipe route, and run a quick test to see the current level.
2. Get a straight quote.For a standard slab home, expect $800 to $1,500. We give you the exact number before we start.
3. Install the system.We cut a suction point, run the pipe, mount the fan, and seal cracks and gaps.
4. Verify with a test.A 48-hour test confirms levels are below 4.0 pCi/L, usually well under.

How long does radon mitigation take?

Most residential radon mitigation systems are installed in a single day. A standard slab-on-grade home takes about four to six hours. Complex jobs, like a house with a crawl space or a steep roof, can stretch into a second day.

The install time depends on how easy it is to run the pipe. A single-story slab with an accessible attic is the quickest. We can be in and out in half a day. A two-story house with a steep roof means more time on the ladder and more care with the flashing. That is where the upper end of the cost range comes from, and it is also where a job can spill into a second morning.

Crawl space homes are a different animal. Instead of cutting a slab, we install a vapor barrier over the dirt and run the pipe under the barrier to a suction point. That is more labor, and it can take a full day. We also have to be careful not to puncture the barrier, because that defeats the purpose.

The post-mitigation test is the part that takes the longest. A short-term test runs 48 hours, and we recommend you keep the house closed up during that time. You can live in the house normally, just keep windows closed and avoid running exhaust fans that could affect the pressure. After the test, we send you the results and you are done.

Our schedule is usually booked a week or two out, depending on the season. Spring and summer are busy because that is when people are getting homes ready to sell. If you are under contract and need the system installed before closing, tell us. We can often move you up.

One thing to know: the fan runs 24/7, so there is no maintenance on your part. The manometer tells you at a glance if the fan is working. If the fluid levels are even, call us. That is the only thing that can go wrong, and it is rare.

Frequently Asked Questions