How to find a radon expert in Norristown, PA

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Norristown compared with other PA cities

Among the 33 Pennsylvania cities with guides on Radon Roster, Norristown ranks #29 by share of basement tests at or above 4 pCi/L. In Montgomery County, compare it with Lansdale, King of Prussia. About 3,410 Norristown basement tests in DEP's records were at or above 4 pCi/L. A DIY or certified test is cheap insurance even where the average is low.

Nearby city guides: West Chester · Erie · King of Prussia · Scranton

Radon mitigation cost: what Norristown homeowners can expect

Source: HomeAdvisor cost guide. These are national figures, not local quotes. Prices depend on foundation type, the number of suction points and pipe routing. Try the estimate tool.

Buying or selling in Norristown? Radon timing tips

• Pennsylvania sellers must give buyers a property disclosure statement before an agreement of sale is signed. The Real Estate Commission's minimum form asks whether the seller knows of hazardous substances "including... radon" and whether the property has been tested (49 Pa. Code § 35.335a; 68 Pa.C.S. Chapter 73).
• Sellers aren't required to test, but must not hide known defects (68 Pa.C.S. § 7308).
• Real estate radon tests by certified testers follow DEP anti-tampering rules, including a signed non-interference agreement (25 Pa. Code Chapter 240). Book the test early in the inspection contingency window, because short-term tests run at least 2 days plus lab time.
• If a result is high near closing, ask certified mitigators for written quotes. Buyers and sellers often negotiate who pays for a system.

General information, not legal advice.

Nearest certified radon firms

Nearest DEP-certified firms: 2 based in Norristown (0 mitigation), 27 elsewhere in Montgomery County (8 mitigation), and 18 mitigation firms in neighboring counties.

See all firms near Norristown →

How to verify a Norristown radon contractor's PA DEP certification

1. Check the name against DEP's current certified mitigation and testing lists in the PA DEP Radon Services Directory. The lists are updated periodically, and ours were retrieved 2026-10-11.
2. Ask for the DEP certification number and photo ID. Pennsylvania requires anyone doing radon testing, mitigation or lab work for the public to be DEP-certified (25 Pa. Code Chapter 240).
3. Still unsure? Call the PA DEP Radon Hotline at 800-237-2366.

Every firm listed for Norristown on Radon Roster shows its DEP IDs and a link to the source list.

Questions to ask a mitigator before you sign

• Who does the follow-up test, and is it an independent certified tester?
• What warranty covers the fan and the work, and is it transferable if I sell?
• Will you seal the sump, cracks or floor-wall joints, and is that in the quote?
• Is a system monitor (manometer or alarm) included so I can see the fan is working?
• Do you carry liability insurance, and will you put the full scope in writing?
• What is your PA DEP certification number, and will you show your DEP photo ID? (Certified people must show it on request under 25 Pa. Code Chapter 240.)

What a typical Pennsylvania radon system install involves

Most systems use active soil depressurization (EPA Consumer's Guide to Radon Reduction). The installer drills a suction point through the basement slab (or seals a crawlspace with a membrane), runs PVC pipe to an inline fan, and vents the exhaust above the roofline. Then they seal major openings and add a pressure gauge. A follow-up test should confirm the level dropped. PA DEP describes the confirm-then-mitigate steps on PA DEP: Radon in the Home.

Frequently asked questions