Photo: Unknown author (public domain), “Radon test kit”, Public domain, via Wikimedia Commons. Resized and converted to WebP; shown cropped.
Radon, mold, asbestos & lead: the basics
Testing and mitigation for radon, mold, asbestos, lead paint and indoor air.
The full guide for this trade is being written. Until then, here is what we know for sure: the problems that belong here, who handles them, and how to check a contractor.
On this page4 sections: urgent, permits…
What people call about
- Radon test
- Asbestos in old floor tile
- Lead paint test
- Mold test
How soon to call
Call in the next day or two
Radon test came back high
Ask for: radon mitigation
Crumbling white insulation on the basement pipes
Ask for: asbestos abatement (licensed)
Do not touch or sweep it; keep the area closed off until it is tested.
Schedule it
Radon test in the basement
Ask for: radon measurement
Old house with flaking paint, could it be lead
Ask for: lead paint testing
Homes built before 1978 may have lead paint; any contractor disturbing it must be lead-safe certified (EPA RRP).
Mold test
Ask for: mold assessment (independent of the remediator)
Asbestos in old floor tile
Ask for: asbestos testing and abatement
Intact tile is usually safe to leave; do not sand, grind or break it.
Popcorn ceiling, could it be asbestos
Ask for: asbestos test before removal
Lead paint test before renovating
Ask for: lead inspection or risk assessment
Indoor air quality test
Ask for: indoor air testing
General guidance, not a diagnosis. If anyone is in danger, call 911 first.
Permits and licensing
- Some of this work needs a permit, depending on the job and the town. Ask before the work starts.
- Licensing depends on the state: a trade license in some, a home-improvement registration in others, none in the rest. The finder shows what the record says where one exists.
Know what you're looking at
Radon is a natural gas that seeps up from the soil into homes. A test is the only way to know your level; fixes (usually a vent pipe and fan) are done by qualified mitigators.
Older roofing, siding and floor tiles can contain asbestos. It is a hazard mainly when disturbed, so a lab test of a small sample comes before any demolition.
Consumer air monitors give a rough read of particles, humidity or carbon dioxide. They are not a substitute for lab testing for mold, radon or asbestos.
General information, not legal, tax, engineering or insurance advice. Rules and prices vary by place, so get three local quotes. Problem list updated 2026-10-04.