How Do I Read My Mold Clearance Report? What the Numbers Actually Mean

By the Cowboy K9 team · 6 min read

A mold clearance report tells you whether the air in a remediated area is back to normal — and the way it does that is by comparison, not by a single magic number. In plain terms: you “pass” when the mold spore levels inside the cleaned area are at or below the levels outside your home, and the water-damage mold types that caused the problem in the first place are essentially gone. If you just had remediation done anywhere around Bluffton or Hilton Head Island and you’re staring at a lab sheet full of numbers, here’s how to make sense of it.

What do the spore-count numbers mean?

Most air-sample reports show two figures per sample. The raw count is how many spores the lab actually counted on the collection slide. The spores per cubic meter (often written spores/m³ or Cts/m³) is the calculated concentration in the air — that’s the number you use for comparison. The report lists these by mold type, and it will almost always include an outdoor sample and one or more indoor samples. Certain types are treated as “water-damage indicators” — names like Stachybotrys, Chaetomium, and elevated Aspergillus/Penicillium — because they point to an active indoor moisture problem rather than normal outdoor drift.

How do I know if I actually passed?

Three things generally signal a clean clearance. First, indoor spore concentrations are lower than or similar to the outdoor sample — outdoor air is the natural baseline, so indoor levels sitting at or below it is what you want. Second, the mix of species indoors looks like the mix outdoors, rather than being dominated by one type. Third, the water-damage indicator molds that triggered the original job are not showing up at meaningful levels inside. If your indoor numbers are well above outdoor, or a marker species is still present in the cleaned space, that’s the report telling you the work isn’t finished. When in doubt, ask the company that read the samples to walk you through the comparison line by line.

It also helps to read the report alongside the visual inspection notes, not in isolation. A clean air sample means little if there’s still visible growth, a lingering musty smell, or a moisture source that was never fixed — and a slightly elevated number can be harmless if it matches what’s drifting in from outside on a Lowcountry summer day. Good clearance is really three things agreeing: the visual is clean, the moisture problem is corrected, and the numbers back it up. If those three don’t line up, the report is doing its job by flagging it.

A clearance test isn’t a grade out of 100 — it’s a before-and-after comparison against the air outside your own front door.

Where does a mold dog fit in?

Air sampling captures a moment in time at the spots where the samples were pulled. A canine sweep is a fast, non-invasive way to cover the whole living space in between or alongside those samples: Cowboy alerts to the gases active mold gives off, often far below what a person can smell, so if a room reads “clear” on paper but something was missed nearby, he can point you back to it. Plenty of homeowners across Beaufort County use a dog inspection as an independent second opinion after remediation — not to replace the lab report, but to make sure nothing hidden got left behind before the containment comes down for good. Seek. Alert. Inform.