In short: “black mold” is a description of color, not a diagnosis. Any dark growth is removed the same careful way: seal the area, put it under negative air, cut out what it has rooted into, HEPA clean, dry and clear. In Tampa that typically runs $10–$25 per affected square foot, or $1,200–$3,000 for one contained area, as estimates.
Is it Stachybotrys?
The mold people mean by “toxic black mold” is usually Stachybotrys chartarum, which grows on drywall paper and wood that has stayed wet for a long time. Plenty of other dark molds look the same, and you can’t tell them apart by eye. Only a lab can. For removal it matters less than people expect: the containment and removal steps are the same, so the money is usually better spent on fixing the leak than on identifying the species.
Why we cut it out instead of spraying it
Growth on drywall sends roots into the paper and gypsum behind the surface. Spraying it kills some of what you can see and leaves the rest in place, and dead spores still cause reactions in sensitive people. So porous material with growth on it is cut out past the visible edge, bagged inside the containment and taken out of the house. Framing that is sound gets cleaned, sanded where needed and HEPA vacuumed.
Where we find it in Tampa homes
- Behind the toilet and under the vanity, from a slow supply-line drip.
- On the back of drywall around windows with failed flashing.
- Inside the closet that holds the air handler, from a blocked condensate line.
- Along the bottom of exterior walls after storm water came in under the door.
Price guide
| Job | Estimated price | What drives it |
|---|---|---|
| One contained area | $1,200–$3,000 | Square footage and access |
| Per affected sq ft | $10–$25 / sq ft | Depth into framing |
| Full room or several cavities | $2,500–$6,000 | Number of walls opened |
These figures are estimates. Rebuild (new drywall, paint, trim) is priced separately so you can compare it, or hand it to your own contractor.
Black mold removal: common questions
Is black mold dangerous?
Any mold can trigger allergy and asthma symptoms, and people with weak immune systems are more at risk. If anyone in the home has symptoms, talk to a doctor; we deal with the building.
Can I clean a small patch myself?
The EPA’s guidance is that an area under about 10 square feet can often be cleaned by a homeowner with gloves, eye protection and an N95, as long as the water problem is fixed. Larger areas, or anything inside walls or the AC, need containment.
Will painting over it stop it?
No. Paint seals the stain in, not the moisture out, and the growth carries on underneath.
Last reviewed October 8, 2026.