Radon Mitigation Systems: 6 Types Every Homeowner Should Know

When it comes to keeping your family safe from radon gas, knowing your options is half the battle. There are several different radon mitigation systems available, and the right one for your home depends on your foundation, layout, and the level of radon detected. While each system works a little differently, they all share the same goal: reducing radon levels indoors and making your home healthier.

Key Takeaways

• Radon mitigation systems are designed to lower radon levels to safer limits.
• There are six main types, each suited for specific home designs and conditions.12
• Sub-slab depressurization is the most common and effective method for many homes.
• Crawl spaces often require specialized systems like sub-membrane depressurization.
• Professional installation is recommended for lasting, reliable results.

Why Radon Mitigation Systems Matter

Radon is an invisible gas that seeps up from the ground and can build up indoors. Long-term exposure is linked to serious health problems, including lung cancer. Testing is the first step to knowing your risk, but if your home tests high, installing a mitigation system is the next critical step.

Think of radon mitigation like waterproofing your basement. You might not see water every day, but when it leaks in, it can cause major problems. In the same way, radon doesn’t announce itself — but mitigation ensures it doesn’t threaten your home and health.

The 6 Types of Radon Mitigation Systems

Let’s break down the six most common radon mitigation systems, how they work, and when they’re used.

1. Sub-Slab Depressurization

This is by far the most widely used and effective system. A fan and PVC piping are installed to draw radon gas from beneath the home’s foundation and vent it safely above the roofline.

Best For: Homes with basements or slab-on-grade foundations.

Cost in Arizona: Typically $1,200 – $2,500, depending on slab thickness and number of suction points.

Pros:

• Highly effective at lowering radon.
• Works in most soil types.
• Long-lasting if properly maintained.

Cons:

• Requires professional installation.
• Involves drilling through the slab, which adds to the cost.

2. Sub-Membrane Depressurization

For homes with crawl spaces, this system is often the best choice. A heavy plastic sheet (vapor barrier) is laid over the soil, sealed at the edges, and connected to a vent pipe and fan that draw radon out from under the membrane.

Best For: Homes with exposed dirt crawl spaces.

Cost in Arizona: Typically $1,500 – $2,500 due to labor and materials.

Pros:

• Extremely effective in crawl spaces.
• Provides moisture control in addition to radon reduction.

Cons:

• Requires durable materials and expert sealing.
• More labor-intensive than some other systems.

3. Crawl Space Ventilation

Instead of sealing off the crawl space, this method increases airflow by installing vent fans or passive vents. The goal is to dilute radon by moving it outside before it seeps into the living areas.

Best For: Homes with smaller crawl spaces or mild radon levels.

Cost in Arizona: $800 – $1,500, depending on the number of vents and fans needed.

Pros:

• Relatively low-cost compared to other systems.
• It can improve overall air circulation.

Cons:

• Less effective in high-radon situations.
• May increase energy costs by bringing in outside air.

4. Sealing Cracks and Openings

This method involves sealing visible cracks, gaps, and openings in basement floors, foundations, and crawl space walls. While not effective as a standalone solution, it is often used in combination with other systems.

Best For: Homes with visible foundation cracks.

Cost in Arizona: $300 – $800, depending on the number and size of cracks.

Pros:

• Affordable and simple to do.
• Supports other mitigation methods.

Cons:

• Not effective on its own.
• Requires regular maintenance as cracks reappear over time.

5. Heat Recovery Ventilator (HRV)

An HRV system brings in fresh outdoor air while exhausting indoor air, creating a balanced airflow that helps reduce radon levels. This system also improves overall indoor air quality.

Best For: Homes with moderate radon levels and poor ventilation.

Cost in Arizona: $1,000 – $2,000 for installation.

Pros:

• Improves air circulation.
• Can lower humidity and odors, as well as radon.

Cons:

• More expensive than basic ventilation.
• Less effective than sub-slab depressurization in high-radon areas.

6. Passive Radon Mitigation Systems

These systems are built into newer homes during construction. They use natural airflow and pressure differences to vent radon outdoors without a fan. If radon levels later test high, the system can usually be upgraded to an active one by adding a fan.

Best For: New construction homes.

Cost in Arizona: $800 – $1,500 during initial build; $500 – $800 to upgrade later.

Pros:

• Inexpensive to install during building.
• No energy costs if used passively.

Cons:

• It may not reduce radon enough on its own.
• Often requires upgrading to an active system.

Comparing the Systems

Here’s a quick side-by-side look at how these six radon mitigation systems stack up:

System Type	Best Suited For	Effectiveness	Cost Range	Notes
Sub-Slab Depressurization	Basements, slab-on-grade	Very High	$1,200–$2,500	Most common system
Sub-Membrane Depressurization	Crawl spaces	Very High	$1,500–$2,500	Also reduces moisture
Crawl Space Ventilation	Mild radon levels, crawl spaces	Moderate	$800–$1,500	Energy use may increase
Sealing Cracks	Any home	Low (alone)	$300–$800	Works best with other systems
Heat Recovery Ventilator (HRV)	Homes with poor ventilation	Moderate	$1,000–$2,000	Improves overall air quality
Passive Systems	New builds	Moderate	$800–$1,500	Can be upgraded later

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Arizona Context for Radon Mitigation Systems

Arizona’s unique soil and climate conditions shape which system is most effective:

• Northern Arizona (Flagstaff, Prescott) has granite-heavy soil and more crawl spaces, making sub-membrane systems common.
• Central Arizona (Phoenix, Scottsdale) has more slab-on-grade homes, so sub-slab depressurization is typically used.
• Southern Arizona (Tucson, Sierra Vista) often has a mix, with some homes benefiting from HRVs to combat poor ventilation.

No matter the region, tight home construction for energy efficiency can trap radon indoors, making active systems more necessary.

Homeowner Checklist

Choosing among different radon mitigation systems can feel overwhelming. This checklist makes it easier:

1. Test Your Home
   • Short-term test → initial snapshot.
   • Long-term test → more accurate average.
2. Know Your Foundation
   • Basement? → Sub-slab depressurization is most common.
   • Crawl space? → Sub-membrane or ventilation.
   • Slab-on-grade? → Sub-slab system with suction points.
3. Consider Your Budget
   • Entry-level → sealing cracks and basic ventilation.
   • Mid-range → HRV or crawl space ventilation.
   • High-performance → sub-slab or sub-membrane depressurization.
4. Think Long-Term
   • Factor in fan replacement every 5–10 years.
   • Retest regularly to ensure system effectiveness.

Frequently Asked Questions

Can I install a system myself?
Some DIY steps, like sealing cracks, are fine. But full systems are best handled by certified professionals to ensure effectiveness.

Do mitigation systems use a lot of electricity?
No. Fans typically cost $30–$90 per year in energy.

Will pipes be visible?
Yes, vent pipes are usually visible on the outside of the home, though contractors can often route them discreetly.

How quickly will radon levels drop?
Most systems reduce radon within 24–48 hours.

Will I need to test again after installation?
Yes. Follow-up testing is essential to confirm success. Retesting every two years is recommended.

Review

Radon mitigation systems come in several forms, but they all serve the same purpose — lowering radon to safe levels so your family can breathe easy. Whether you’re in Phoenix with a slab foundation, Flagstaff with a crawl space, or Tucson with ventilation concerns, there’s a system built for your situation.

The important part is taking action. Radon is invisible, but your safety plan doesn’t have to be. Test your home, talk with a certified professional, and choose the system that fits your needs. With the right approach, you’ll not only reduce risk but also add long-term value and peace of mind to your home.