How Long Does Radon Mitigation Take?

The short answer

Most radon mitigation systems are installed in 4–8 hours on a single day. From the time you contact a professional to when your system is running, the total timeline is typically 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)

The first step is contacting certified professionals in your area. Most homeowners get 2–3 quotes before proceeding.

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

What affects your wait time:

• Availability: In high-radon provinces like Saskatchewan and Manitoba, certified professionals may have 2–4 week wait lists during peak seasons (fall and early winter)
• Your schedule flexibility: Professionals can usually accommodate within 2–3 weeks if you're flexible on timing

Tip: Contact multiple professionals simultaneously, not sequentially. Find certified professionals near you.

Phase 2: Installation day (4–8 hours)

Installation of a standard sub-slab depressurization system is almost always a single-day job. For most homes, it takes 4–8 hours.

What happens during installation:

1. Core drilling: The installer drills one or more suction holes through the concrete slab (or crawlspace floor) to access the sub-slab soil.
2. Suction pit verification: They test to confirm the soil under your slab communicates well with the drilling point — good communication means one suction point will be enough.
3. PVC pipe routing: Suction pipes are run from beneath the slab, up through the home's interior or exterior, and to the 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. Most installations require a simple electrical connection.
6. Manometer installation: A small pressure gauge (manometer) is installed on the pipe to confirm the system is actively creating negative pressure under your slab.
7. Sealing: Any cracks, sump lids, or exposed soil entry points visible in the basement are sealed with caulk.
8. Final test and walkthrough: The installer runs a final check, explains the system, and advises on post-installation testing.

Larger or more complex homes — multiple zones, block walls instead of poured concrete, crawlspaces, or significant foundation cracks — may require a longer installation 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 your radon levels. You have two options:

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

A certified measurement professional places continuous monitors for 48–96 hours, at least 24 hours after your mitigation system has been running. Results confirm whether the system is working and provide certified documentation.

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

Long-term DIY test (91+ days)

Place an alpha track test kit in the lowest liveable area and leave it for 91+ days. This gives you the most accurate long-term picture of your actual living environment with the system running.

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

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

What does a typical result look like?

A well-installed sub-slab depressurization system typically reduces indoor radon levels by 80–99%. If your home tested at 500 Bq/m³ before mitigation, a successful system should bring you to 50–100 Bq/m³ or lower.

If your post-mitigation test 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 itself is permanent — it's built into your home. The fan runs continuously, typically for 5–10 years before needing replacement (fan life varies by model). Replacement fans cost $200–$500 and can usually be installed by a handy homeowner or your original installer.

You should re-test your radon levels every 2–5 years to confirm the system continues to perform. Radon levels can change if your foundation develops new cracks, if you renovate, or if soil conditions shift.

Annual checks to do yourself:

• Look at the manometer gauge — it should show negative pressure (liquid on one side higher than the other, or a digital negative 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 pressure or positive pressure, your fan may have failed — contact your installer.

How much does it cost?

In most Canadian markets, a standard radon mitigation 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 our guide: How Much Does Radon Mitigation Cost in Canada?

Government rebates may be available in your province to offset the cost — see our Radon Rebates Guide.