Surface sampling is designed to identify whether mold is physically present on a specific surface. It is useful for confirming mold on walls, ceilings, furniture, personal belongings, or building materials. Unlike air sampling, which only captures spores that are airborne, surface sampling allows you to test settled or growing mold directly.

Here’s what it can and can’t tell you:

What it can detect:

• Visible mold growth on solid surfaces.
• Hidden mold growth in cracks, grout lines, or under finishes.
• Contamination on belongings or materials after a leak or exposure.

What it can’t detect:

• Airborne mold exposure.
• Mold behind surfaces unless you can swab it directly.
• The full extent of a problem—just whether mold is present on the sampled spot.

Surface samples also don’t measure how much mold is present in terms of spore count. They are qualitative (telling you what is there), rather than quantitative (how much is there), unless cultured and counted. That said, even a basic identification can be very helpful when evaluating items to clean or discard, or when deciding whether professional help is needed.