A mold inspection and a mold test are different things. A mold inspection is a visual check of your home by someone who knows where mold hides: they look for growth, water stains, leaks and damp materials, often with a moisture meter. Mold testing means taking air or surface samples and sending them to a lab to count and identify spores. The EPA says that when you can already see mold, testing is usually unnecessary, and the CDC does not recommend routine testing. An inspection to find hidden mold and its moisture source is often the more useful thing to pay for. This page explains when each one helps, what the results mean, and how to ask for quotes.
Do you need a mold test, or a mold inspection?
Most people need an inspection more than a test. If you can see or smell mold, an inspection finds how far it has spread and where the water is coming from, which is what decides the fix. A lab test mainly adds a spore count, and the EPA notes there are no federal limits to compare that count against.
A test can be worth paying for when:
- you smell mold but can't find it, and an inspector suspects it is inside a wall, ceiling or duct
- remediation is finished, and you want clearance samples to check the area was cleaned properly. The EPA says surface sampling can help confirm this
- a home sale, a lease or a dispute needs a written record from a third party
- a doctor has asked about mold exposure at home
If a business offers testing as part of a remediation quote, ask what the result would change about the work.
What happens during a mold inspection?
A mold inspection is a room-by-room check for visible growth, moisture and the conditions that cause mold. The inspector looks in the places people don't: the crawl space, the attic, under sinks, around windows, behind the washing machine and at the heating and cooling system. They often use a moisture meter and sometimes a thermal camera to find damp spots behind walls.
What a good inspection report includes:
- Where mold was found, and roughly how much
- Where the moisture is coming from, such as a leak, condensation, humidity or drainage
- Photos of what they found
- Indoor humidity readings. The EPA recommends keeping indoor relative humidity below 60 percent, ideally between 30 and 50 percent
- What they recommend, and whether samples were taken and why
What does a positive mold test mean?
A positive mold test means mold spores were found in the sample, which is true of almost any home, because spores are always in outdoor air and come indoors. What matters is how the indoor sample compares with an outdoor sample taken at the same time, and which types of mold were found. That is why results need someone experienced to read them.
The EPA says sampling should be done by professionals with experience in designing sampling and reading the results, and that labs should follow methods from bodies like the American Industrial Hygiene Association. If a test shows growth indoors, the next step is the same as if you had seen it: find the moisture, remove the mold, and fix the cause.
Are home mold test kits accurate?
Home mold test kits can tell you that mold spores are present, but that is true of almost every home, so a positive result doesn't tell you much on its own. Most settle-plate kits catch whatever spores land on the dish, with no measure of how much air was sampled. They can't tell you where mold is growing or why.
Our guide to DIY mold test kits goes into what the different kits measure, and when your money is better spent on an inspection. If you can see mold already, the EPA says you don't need a test to know it is there.
How much does mold testing cost in Charlotte?
Mold inspection and testing prices vary a lot between businesses in Charlotte, depending on the size of the home, how many samples are taken, and whether lab fees are included. Some remediation businesses inspect free and charge for samples. Independent inspectors usually charge a set fee plus a fee per sample.
When you compare quotes, ask:
- Is the inspection free, or a set fee?
- How many samples, and where? Is an outdoor sample included for comparison?
- Are lab fees included, and how long do results take?
- Will I get a written report with photos?
- Is the inspector separate from the business that would do the remediation?
Clearance testing after remediation is often an extra charge, according to This Old House. Ask about it before the work starts.
Questions people ask
Can I do a mold inspection myself?
You can do a basic check yourself. Look and smell around sinks, toilets, windows, the water heater, the attic and the crawl space. Look for water stains, peeling paint, warped wood and condensation, which the EPA lists as signs of a moisture problem. What you can't easily check is inside walls and ducts, which is where a professional inspection earns its fee.
Is there a mold test you can use on yourself?
Mold tests for homes test samples from the air or surfaces, not your body. If you are worried that mold is making you ill, that is a question for a doctor, who can decide what tests make sense. The CDC notes that no test can show that a particular mold caused particular symptoms, so the focus is on your symptoms and on fixing the mold at home.
What are the signs of mold in a house?
Common signs are a musty smell, visible spots on walls, ceilings or grout, water stains, peeling or bubbling paint, and condensation on windows or pipes. The EPA notes mold can hide on the back of drywall, wallpaper or paneling, and above ceiling tiles. Allergy-like symptoms that ease when you leave the house can also be a clue.
How do I test my house for mold and mildew?
For mildew on a bathroom surface, you don't need a test: if it wipes off and comes back, it is surface mold, and the fix is cleaning and better ventilation. For mold you can smell but not see, a professional inspection with a moisture meter usually finds it faster than a test kit. Lab samples help if the source still can't be found.
Can you test for mold spores in the air?
Yes. Air sampling pulls a measured amount of air through a cassette that traps spores, and a lab counts and identifies them. It is usually done indoors and outdoors at the same time, so the two can be compared. The EPA says the results should be read by someone experienced, because there are no federal limits to compare them with.
Guides in this section
- DIY mold test kits
What DIY mold test kits actually measure, why almost every kit comes back positive, and when a professional inspection is a better use of…
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