What should I ask before hiring a radon mitigation contractor?

Ask what test result triggered the quote, what foundation type and suction method the quote assumes, what fan and warranty are included, whether permits or electrical work are included, and how the post-mitigation retest will be handled.

What is a red flag in a radon mitigation quote?

A quote is weak if it does not name the system scope, ignores foundation type, excludes obvious sump or crawl-space work, promises a result without a retest plan, or gives a price without explaining what is included.

Contractor quote checklist

Ask better radon quote questions before you hire.

Use this call script to compare radon mitigation quotes by result, foundation, scope, fan, permit, warranty, and retest plan.

Build a scoped plan Interpret the test result

Phone script

I have a radon result of ___ pCi/L in ZIP _____. Before I compare prices, can you tell me what system scope your quote assumes, whether sump sealing or crawl-space work is included, what fan and warranty are included, and how the retest will be documented?

Result band Foundation Scope Retest proof

Seven checks

A strong quote names what it includes.

A cheap quote can be fine. A vague quote is the problem. Compare the scope before you compare the price.

Result and test type: short-term, long-term, continuous monitor, real estate test, and exact pCi/L result.

Foundation: basement, slab, crawl space, mixed foundation, sump pit, drain tile, or finished lower level.

Suction method: sub-slab, sub-membrane, drain-tile tie-in, multiple suction points, or passive-system activation.

Fan and warranty: fan model, expected noise, location, warranty length, and who handles a failed fan.

Electrical and permit scope: outlet, dedicated circuit, permit, exterior routing, roofline, and weatherproofing.

Post-mitigation retest: who retests, when it happens, what number is expected, and how the result is documented.

Final price: quoted price, final price if installed, exclusions, deposit, deadline, and payment trigger.

Red flags

Do not compare quotes that describe different jobs.

One contractor may be pricing a simple sub-slab system. Another may be including sump sealing, electrical work, and a documented retest.

Vague scope: "radon system" with no suction method, fan, routing, or sealing details.

Missing retest plan: no timeline for proving the system lowered the reading.

Foundation ignored: crawl-space or sump work treated like a standard basement job.

Unclear exclusions: electrical, permit, patching, fan warranty, or exterior routing left out.

After the call

Turn the quote into a documented scope.

Preserve the test result, foundation assumptions, suction method, sealing, electrical work, warranty, permit responsibilities, exclusions, and post-mitigation retest plan beside the price.

Build the decision plan Open inspection toolkit

Editorial and Data Transparency

Author: RadonVerdict (Independent public-data software project)
Evidence Review: Official and primary sources cited below
Data Retrieved At: Source-level dates below

Primary Sources

EPA Map of Radon Zones (retrieved 2026-02-21)
EPA A Citizen's Guide to Radon (retrieved 2026-05-05)
CDC Environmental Public Health Tracking - Radon Testing (retrieved 2026-05-05)
Angi Radon Mitigation Cost Guide (retrieved 2026-02-21)