A mold inspection is a visit by a trained inspector to find out whether mold is growing in your home, how far it has spread, and, most important, what moisture is feeding it. It is not the same as a mold test, which analyzes samples in a lab, although an inspection can include testing.
This guide explains what happens during an inspection, when sampling is worth it, what the report should tell you, and who is qualified to do the work. If you are ready to book, see our page on mold inspection services.
Inspection, testing, and assessment: what the words mean
- Mold inspection. A visual and instrument-based search for mold growth and moisture problems.
- Mold testing. Collecting air, surface, or material samples and sending them to a lab. Testing is one possible part of an inspection. See mold testing.
- Mold assessment. The term many state laws use for the professional process of inspecting, sometimes sampling, and writing a plan for removal. In Florida and Texas, mold assessment is a licensed activity.
An inspection is about the building, not your health. An inspector can tell you where mold is and why it is there, but not whether it is causing symptoms. That is a question for a doctor.
What happens during a mold inspection
Most inspections follow the same sequence:
- Questions first. The inspector asks what you have noticed: a smell, stains, a past leak or flood, or areas where mold keeps coming back.
- Visual walk-through. The inspector checks rooms and closets and the places where water tends to collect: under sinks, around tubs and showers, windows, the water heater, the attic, crawl spaces, and the air handler and ducts.
- Moisture readings. A moisture meter shows whether drywall, wood, or flooring is wet. The readings help trace a leak back to its source.
- Thermal imaging. Many inspectors use an infrared camera. It does not see mold. It shows temperature differences that can reveal damp areas inside walls and ceilings.
- Humidity and temperature. Readings show whether the indoor air itself is feeding growth. The EPA recommends keeping indoor humidity below 60 percent, ideally between 30 and 50 percent.
- Sampling, if needed. Samples are taken when they answer a question the visual inspection cannot.
- Findings. You get a verbal summary on site and, depending on the service, a written report.
Air, surface, and material samples
| Sample type | What it shows | Limits |
|---|---|---|
| Air sample (spore trap) | Types and levels of spores in indoor air, usually compared with an outdoor sample | A snapshot of one moment; levels change during the day |
| Surface sample (tape or swab) | Whether a stain is mold, and what kind | Shows only the spot sampled |
| Bulk sample | Mold on or in a piece of material, such as drywall or carpet | Requires removing material |
No EPA or other federal limits have been set for mold or mold spores, so a lab result cannot show whether a home passes a federal standard. That is why the EPA says sampling is unnecessary in most cases when mold is visible, and that it should be done by professionals with experience in designing sampling plans and interpreting results. Sampling is most useful to look for hidden growth, to compare indoor air with outdoor air, or to confirm that cleanup worked.
What the report should include
A useful inspection report covers:
- Where mold was found, with photos
- Moisture readings and the likely water source
- The approximate size of each affected area
- Lab results, if samples were taken, with the name of the lab
- Recommendations: what has to be removed, what can be cleaned, how the area should be contained, and what must be repaired to stop the moisture
In states that license mold assessors, such as Florida, the assessor's written plan is often called a remediation protocol, and the remediation company works from it.
How long a mold inspection takes
A typical inspection takes a few hours on site. Larger homes, or cases where the inspector has to check a crawl space or open a small section of wall, take longer. Lab results for any samples usually arrive within a few business days, and the written report follows.
Do you need a mold inspection?
An inspection is worth it when:
- You smell mold but cannot find it
- You have had a flood, a roof leak, or a plumbing leak that soaked walls or floors
- Mold keeps returning after cleaning
- You are buying or selling a home and want to know what is behind the walls
- You are filing an insurance claim and need to document the damage
- Remediation is finished and you want to confirm the area is clean
You may not need one when the mold is small, visible, and has an obvious cause that has been fixed. The EPA says areas smaller than about 10 square feet, roughly a 3 by 3 foot patch, can often be cleaned by the homeowner, provided the moisture problem is solved.
Who does mold inspections
Who is allowed to inspect depends on where you live:
- States that license mold work. Florida, Texas, New York, and Washington, D.C. license mold assessors. There, ask for the license number and check it with the state before the visit.
- Everywhere else. Most states do not license mold inspectors, so credentials matter more. Look for industrial hygienists or inspectors with recognized mold certifications, ask how they sample and which accredited lab they use, and ask to see a sample report.
- Home inspectors. A standard home inspection before a purchase usually notes visible mold and signs of moisture, but it does not include sampling or a full mold assessment.
Also ask whether the inspector does removal. An inspector who does not sell remediation has no stake in the size of the job.
Who pays for a mold inspection
The homeowner usually pays. When buying a home, the buyer normally pays for an inspection during the inspection period. For rentals, the landlord typically arranges and pays for it. If the mold follows a covered insurance loss, some policies count testing toward the mold limit; see does homeowners insurance cover mold.
What a mold inspection costs
National cost data puts most inspections at roughly $300 to $1,000, with an average near $670. The price rises with the size of the home, the number of samples, and how hard the attic and crawl space are to reach. Our mold inspection cost guide has the details, and our guide to free mold inspections explains what a no-cost visit usually includes.
How to prepare for the visit
- Do not clean, bleach, or paint over suspected mold beforehand
- Write down when you noticed the problem, any leaks, and any past repairs
- Clear access to the attic, crawl space, water heater, and air handler
- Follow the inspector's instructions before air sampling; many ask that windows and doors stay closed for several hours beforehand
Mold inspections in Florida
Florida requires a DBPR mold assessor license for most mold assessments involving more than about 10 square feet, and the assessor generally cannot remediate the same home within 12 months. Verify the license at myfloridalicense.com before the visit. See the Florida state page or local pages such as Fort Lauderdale, West Palm Beach, and Sarasota.
Next step
If you own your home and want a professional to look at it, call the number on this page to be connected with an independent local mold inspection company. You can also start from our mold inspection and mold testing pages.