Mold testing takes air or surface samples, sends them to a lab, and tells you what is growing and roughly how much. It is worth it for growth you cannot see or reach. If you can already see or smell the mold, the CDC says you do not need to know the type, because it should be removed either way (cdc.gov). Lab testing is $350 for two samples and $450 for four.
When is a test worth it, and when is it not?
Worth it when nobody can find the source: a smell with no visible growth, a suspicion about what is behind a wall or above a ceiling, a house you are buying, or a landlord and tenant who need something in writing that neither of them wrote.
Not worth it when you are looking straight at it. The EPA and the health departments take the same line: if you can see or smell mold, clean it up and dry out the area rather than pay to identify it. The CDC agrees on species: you do not need to know what type of mold it is, because it should be removed either way (source).
Testing does not fix anything on its own, and it is not a prerequisite for treatment. A musty smell when the AC runs is a symptom you can act on without a lab report. That path is on why does my AC smell musty.
On-site check or lab test?
Two ways to be certain. An on-site check happens while we are at the house: we swab a surface and read it on a hand-held meter on the spot, which shows how much living material is there. It does not name the mold, and it is not a lab result. A lab test sends air or surface samples to a lab and comes back in writing, which is the one to pick when you need proof for a sale, a landlord or a builder.
What does mold testing cost?
Lab testing is $350 for two samples and $450 for four. Past four samples it depends on how many get taken and where, so that one is quoted on the call and you get the number before anyone comes out.
The treatment prices are on this site. Whole-home disinfection for mold is $0.30 per heated square foot, with a $200 minimum. air duct cleaning and treatment is $50 a vent on the same visit, or from $399 on its own. Dryer vent cleaning is $50 added to a visit, or $99 alone.
What is in a test
- A walkthrough first, looking for water stains, damp spots and the conditions that grow mold.
- Air samples, surface swabs or tape lifts, depending on what the walkthrough turns up. An outdoor sample goes with them as the baseline, because mold is outdoors everywhere and a number with nothing to compare it to means very little.
- Lab analysis, and a written report.
- A moisture assessment, because the water is the part that decides whether the problem comes back.
The part testing cannot tell you
A lab counts what landed on a slide. It does not tell you what to do about it, and it does not tell you where the water is coming from. The EPA is direct about the fix: the key to mold control is moisture control. A report that lists a species and stops there has skipped the only question that matters.
That is also why we lead with the treatment rather than the test. On an HVAC system, what the treatment covers is the same whether a lab has weighed in or not.
Treatment has its own limit. It is not structural mold remediation, and it does not fix an active leak. Moisture that is still wet can grow mold again, so we look for the water first and tell you what we find.
Frequently asked questions
Do I need a mold test before treatment?
No. If you can see it or smell it, the CDC’s position is that the type does not change what happens next: it gets removed (cdc.gov). Testing is for growth nobody can find.
What does a mold test cost?
Lab testing is $350 for two samples and $450 for four. Past four samples it is quoted on the call, because the number depends on how many get taken and where.
What kinds of samples are there?
Air sampling, surface swabs and tape lifts. Which one fits depends on whether you are chasing something in the air or something on a surface.
Will a test tell me if my house is safe?
No, and be careful of anyone who says it will. A sample says what was in that spot at that moment. What it is good for is finding growth you cannot see and pointing at the water feeding it.
When should I test?
When you smell something and cannot find it, when you suspect water got somewhere you cannot see, or when you are buying a house and want it in writing before you sign.
Ask about a test
Leave your number in the form below and say what you are chasing. We call you back with what a test would cost for your house.
Tell us about the house
Send us the house and the price comes back in writing before anyone comes out.