How Long Does Radon Mitigation Take?

Most radon mitigation systems are installed in 4–8 hours on a single day. From first contact with a professional to a running system, the total timeline is usually 2–6 weeks, depending on contractor availability and your schedule.

To confirm the system is working, you'll need to wait at least 24 hours for a short-term professional post-mitigation test, or 91+ days for a long-term DIY confirmation.

Phase 1: Getting quotes (1–3 weeks)

Start by contacting certified professionals in your area. Most homeowners get 2–3 quotes before deciding.

• Initial contact to response: Most reputable contractors reply within 1–3 business days
• Site assessment: Some quote over the phone or video; others want to see your foundation type in person
• Quote turnaround: 1–5 business days after assessment

In high-radon provinces like Saskatchewan and Manitoba, contractors can have 2–4 week wait lists during fall and early winter. The busier the market, the longer the lead time. If your schedule is flexible, most professionals can fit you in within 2–3 weeks.

Contact multiple professionals at the same time, not one at a time. Find certified professionals near you.

Phase 2: Installation day (4–8 hours)

For most homes, installation is a single-day job lasting 4–8 hours. Here's what happens:

1. Core drilling: The installer drills one or more suction holes through your concrete slab to reach the sub-slab soil
2. Suction pit verification: They test whether the soil beneath communicates well with the drilling point (good communication means one suction point is likely enough)
3. PVC pipe routing: Suction pipes run from beneath the slab, up through the home, and to a fan mounted outside or in the attic
4. Fan installation: A continuously running radon fan is mounted outside or in an unconditioned space, never inside living areas
5. Electrical connection: The fan is wired to a nearby circuit
6. Manometer installation: A small pressure gauge is installed on the pipe to confirm the system is creating negative pressure under your slab
7. Sealing: Visible cracks, sump lids, or exposed soil entry points in the basement are sealed with caulk
8. Final walkthrough: The installer runs a final check and explains how to monitor the system going forward

Homes with complex foundations, multiple zones, block walls instead of poured concrete, or crawlspaces may need extra time or a second visit.

Phase 3: Confirming the system works (1 day to 3+ months)

Your system is running, but you need to verify it's actually lowering radon levels. Two ways to do this:

Short-term professional post-mitigation test (1–2 days)

A certified professional places continuous monitors for 48–96 hours, at least 24 hours after your system starts running. You get a documented result confirming the system is working.

Cost: ~$150–$300. Find a measurement professional near you.

Long-term DIY test (91+ days)

Place an alpha track kit in the lowest livable area and leave it for 91+ days. This gives you the most accurate long-term picture.

Cost: ~$30–$60. See our DIY Testing Guide for kit options.

Many homeowners do both: a professional short-term test right after installation for quick confirmation, and a long-term DIY test a few months later for a reliable baseline.

What results to expect

A well-installed sub-slab depressurization system typically reduces indoor radon by 80–99%. A home at 500 Bq/m³ before mitigation should come down to 50–100 Bq/m³ or lower.

If post-mitigation testing still shows elevated levels, your installer may need to add a second suction point, increase fan capacity, or seal additional entry points. This happens in a minority of cases and is covered under most professionals' workmanship warranties.

Summary timeline

Is radon mitigation permanent?

The system is built into your home and lasts indefinitely. The fan runs continuously, typically for 5–10 years before needing replacement. Replacement fans cost $200–$500 and can usually be installed by a handy homeowner or your original contractor.

You should retest every 2–5 years to confirm the system keeps performing. Radon can change if your foundation develops new cracks, if you renovate, or if soil conditions shift.

Annual checks you can do yourself:

• Look at the manometer: it should show negative pressure (liquid displaced to one side, or a negative digital reading)
• Listen for the fan: it should be running quietly
• Check for visible damage to the exterior pipe or fan housing

If the manometer shows equal or positive pressure, the fan may have failed. Contact your installer.

How much does it cost?

In most Canadian markets, a standard system costs $1,500–$3,500 installed. Complex foundations, multi-zone systems, and remote locations can push costs higher.

For detailed cost information by province, see: How Much Does Radon Mitigation Cost in Canada?

Government rebates may be available depending on your province: Radon Rebates Guide.