Guide

How to Choose a Radon Mitigation Contractor

What to verify

• Active PA DEP radon certification, checked in the state's public database, not just taken on the contractor's word
• A written system design specific to your foundation type, not a generic flat quote given sight-unseen
• Whether post-mitigation testing is included in the price or billed separately
• General liability insurance, separate from DEP certification
• A clear explanation of where the fan and exterior vent pipe will be placed, since a poorly placed vent can create a nuisance for neighbors or re-entry into the home

Red flags

• Anyone who can't produce an active DEP certification number when asked directly
• A quote given without ever seeing the foundation
• No mention of post-mitigation testing to confirm the system worked
• Pressure to sign immediately with a large same-day discount

Why certification matters more here than in most trades

This isn't a "nice to have" credential, it's the law in Pennsylvania (see radon mitigation in York, PA for the specific statute), and it exists because a poorly designed system can fail to actually lower radon levels while giving a false sense that the problem is solved. A DEP certification means the installer has completed training specifically in system design and radon physics, not just general HVAC or construction experience.

Verify the certification first, and do it yourself

Pennsylvania is unusual in requiring state certification for radon work. Most states do not. Anyone testing or mitigating radon for compensation here must hold an active PA DEP certification under the Radon Certification Act (Act 43 of 1987, 25 Pa. Code Chapter 240), and the list is public.

Ask for the certification number, then look it up in DEP's own database rather than accepting a photograph of a card. A quote from an uncertified installer is not a bargain in Pennsylvania, it is an illegal transaction, and it will not hold up when a buyer's agent asks for the number.

The questions that separate a good quote from a cheap one

1. What is your PA DEP certification number, and may I look it up?
2. Will you do communication testing before choosing the suction point, or are you estimating from the floor plan?
3. How many suction points, and where exactly?
4. Interior or exterior pipe route, and what will it look like from the street?
5. Which fan model, what is the warranty, and what does a replacement cost in five years?
6. Where does the vent terminate relative to the roofline and the nearest window?
7. Is a post-mitigation test included, and what happens if the result is still above 4 pCi/L?
8. Will you guarantee a specific number in writing, not just "we will get it down"?
9. Does my borough or township require a permit, and are you pulling it?
10. What is sealed as part of the job, and is the sump lid included and still removable?

Question seven is the one that matters most. A guarantee stated as a number with a defined remedy is a contractual obligation. "We will get it down" is a sentiment.

Red flags

• No certification number offered, or reluctance when you ask to verify it
• A quote given over the phone without anyone looking at the foundation
• No post-mitigation test included, or it costs extra
• Pressure to decide today, or a price that expires
• A price that varies with your test result rather than with your foundation
• Offering to handle an insurance claim for you or to waive a deductible
• Selling an air purifier as a radon solution. It is not one
• Proposing to seal cracks as the fix rather than as a supporting step
• Planning to put the fan inside the living space, which is a safety failure, not a preference
• No written scope before work starts

Testing and mitigation by the same company

There is an obvious tension when the party measuring the problem also sells the solution, and it is worth naming rather than pretending it does not exist. It is legal and common, and many certified firms hold both testing and mitigation certifications.

Two things keep it honest. First, you can run the initial short-term test yourself with a fifteen dollar kit, and your result is as valid as anyone's provided closed-house conditions held. Second, the post-mitigation test is the one where independence matters most, and in a real estate context a buyer is entitled to have their own certified measurement professional do it. If anyone objects to that, you have learned something useful.

Related: how testing works, what a homeowner may legally do, what it costs.