How Radon Mitigation Systems Work: A Homeowner's Guide

The Problem: Radon Gas Under Your Foundation

Every home sits on soil that produces some amount of radon gas. In high-risk areas like Twinsburg and Summit County, the glacial clay soil produces enough radon that indoor levels routinely exceed the EPA's 4.0 pCi/L action level. The gas enters through cracks, gaps, sump pits, and the natural porosity of concrete.

A radon mitigation system solves this problem by intercepting the gas beneath your foundation and venting it outdoors before it enters your living space.

Sub-Slab Depressurization: The Gold Standard

The most common and effective radon mitigation method is sub-slab depressurization (SSD). Here is how it works:

1. Suction point — We drill a 4-5 inch hole through your basement floor slab and remove a small amount of aggregate beneath it to create a suction pit.
2. PVC pipe — A sealed PVC pipe connects to the suction point and runs vertically through the house (typically through a closet, utility room, or along an exterior wall) to above the roofline.
3. Radon fan — An inline fan mounted on the pipe creates continuous negative pressure beneath the slab. This reverses the natural pressure gradient that draws radon into your home.
4. Exhaust — The pipe exhausts above the roofline, where radon gas dissipates harmlessly in the outdoor air.

The system runs 24/7 and uses about as much electricity as a 75-watt light bulb. It requires no action from the homeowner beyond occasional visual checks.

How the System Reduces Radon

Without a mitigation system, the air pressure inside your home is slightly lower than the pressure in the soil beneath it. This pressure difference — caused by heating, wind, and the stack effect — pulls soil gas (including radon) into your basement through every available opening.

The radon fan reverses this pressure gradient. By pulling air from beneath the slab, the fan creates a zone of negative pressure under your foundation. Radon gas is drawn toward the suction point instead of into your home, and the fan pushes it up through the pipe and out above the roof.

A single suction point can typically depressurize the sub-slab area beneath an entire home, provided the aggregate layer beneath the slab allows airflow. In homes with multiple foundation sections (such as additions) or poor sub-slab communication, multiple suction points may be needed.

What to Expect During Installation

A typical radon mitigation installation in a Twinsburg-area home takes 4-6 hours. Here is what happens:

• Site assessment — The technician identifies the best suction point location based on foundation type, slab condition, and pipe routing options.
• Core drilling — A 4-5 inch hole is cored through the basement slab. This produces some dust (we use a vacuum attachment) and noise.
• Pipe installation — PVC pipe is routed from the suction point to above the roofline. Interior routing goes through closets, utility areas, or along walls. Exterior routing runs along the side of the house.
• Fan mounting — The radon fan is installed in the attic, garage, or on an exterior section of pipe. It runs continuously and is very quiet.
• Sealing — All visible cracks, gaps, and the sump pit are sealed with caulk and cover plates to maximize system efficiency.
• U-tube manometer — A simple pressure gauge is installed on the pipe so you can visually confirm the fan is creating suction.

After Installation

The system starts working immediately. Within 24 hours, radon levels typically drop to their post-mitigation steady state. We include a follow-up radon test with every installation to document the reduction.

Most homes in the Twinsburg area see post-mitigation levels between 0.5 and 2.0 pCi/L — well below the EPA's 4.0 pCi/L action level. Our systems come with a written guarantee: if post-mitigation levels are not below 4.0 pCi/L, we modify the system at no cost until they are.

Maintenance

Radon mitigation systems are low-maintenance. The fan runs continuously and typically lasts 8-12 years before needing replacement. Check the u-tube manometer periodically — if the fluid levels are even (no pressure difference), the fan may have failed and should be replaced.

We recommend a professional inspection every year and a radon retest every two years to confirm the system is still performing. Learn more about our radon mitigation systems or contact us for a free quote.