{
  "title": "I Found Black Mold — Who Do I Call?",
  "description": "Found black mold? Call a remediation company for anything over 10 sq ft or inside walls; use a separate inspector to test. When it's the landlord's cost.",
  "category": "water",
  "vertical": "water-damage",
  "tldr": "Call a mold remediation company for anything larger than about 10 square feet, or inside walls, HVAC, or after a flood — a small patch on a hard surface you can clean yourself. Use a separate independent inspector for testing, never the company that also sells you the removal. Renting? Notify your landlord in writing first; remediation is normally their cost.",
  "who_to_call": [
    {
      "who": "Independent mold inspector / industrial hygienist",
      "when": "You want to know what and how much before paying for removal",
      "not_for": "You can already see it clearly and it's small — testing adds cost, not information"
    },
    {
      "who": "Mold remediation company",
      "when": "More than ~10 sq ft, inside walls or HVAC, or following water damage",
      "not_for": "A small patch of surface mildew on tile or grout"
    },
    {
      "who": "Water damage restoration company",
      "when": "The moisture source is still active — mold returns unless the leak is fixed first",
      "not_for": null
    },
    {
      "who": "Your landlord (in writing)",
      "when": "You rent — habitability rules in most states make this their responsibility",
      "not_for": "You own the home"
    },
    {
      "who": "Local health department",
      "when": "A landlord ignores a written mold report — many jurisdictions will inspect",
      "not_for": null
    }
  ],
  "body_markdown": "## The 10-square-foot rule\n\nThe EPA's practical dividing line: **under about 10 square feet** (roughly a 3×3 patch) on a hard, non-porous surface, you can handle it yourself — detergent and water, gloves, N95, ventilation, and dry it thoroughly. Skip the bleach; on porous materials it mostly adds water, and the roots survive.\n\n**Above that**, or anywhere mold is inside wall cavities, under flooring, or in the HVAC system, it becomes a containment job. Professionals seal the area under negative pressure precisely so that disturbing the growth doesn't distribute spores through the rest of your house — which is exactly what a homeowner with a scrub brush does.\n\n**Never run the HVAC** if you suspect mold in the ducts. That's a distribution system.\n\n## Fix the water, or you'll pay twice\n\nMold is a symptom. It needs moisture, and it will come back within weeks if the source is still there — a slow supply leak, a roof problem, poor bathroom ventilation, condensation on cold walls, or a humidifier running too high. Any remediation quote that doesn't ask where the water is coming from is a quote to repeat the job.\n\n## Where it's growing tells you which trade fixes the cause\n\nA remediation company removes the mold. A different trade removes the water, and that one is decided by location. Go look at where it's actually growing.\n\n**Bathroom ceiling, or the grout and silicone around the shower** → ventilation, not a leak. You need an extractor fan that runs long enough and vents *outside*, not into the attic. That's an HVAC or electrical contractor. If a fan is already fitted, hold a tissue to it — if it doesn't hold, the fan is decorative.\n\n**On an exterior wall, behind furniture or in a corner, worse in winter** → condensation. Cold wall surface meeting humid indoor air. The fix is insulation, an air gap behind furniture, and humidity control — an insulation contractor, not a plumber, and not a remediator.\n\n**Around window frames and sills** → condensation on the glazing or a failed seal. Window contractor.\n\n**Under a sink, behind a toilet, at the base of a wall backing onto a bathroom** → a live plumbing leak. Plumber first, always, before anyone quotes remediation.\n\n**Dark staining on attic sheathing or the underside of the roof deck** → roof ventilation, or a roof leak. Roofer. Fixr puts attic mold remediation at **$1,500 to $9,000**.\n\n**Inside ducts or on supply registers, smell strongest when the system runs** → HVAC, and turn the system off now; it is a distribution network. Fixr puts HVAC mold remediation at **$3,000 to $10,000**, the most expensive location on the list, which is the argument for not running it.\n\n**Crawl space, with a musty smell that shows up throughout the house** → ground moisture rising through the floor. Encapsulation and a vapour barrier; a crawl space or foundation contractor. Fixr puts crawl space mold at **$500 to $2,000**. If a floor above it has gone soft or bouncy, the wood is already involved — [that sequence has its own page](/home/soft-spot-in-floor/), including which quotes are diagnosis and which are inventory.\n\n**Basement walls or the floor slab** → groundwater through the foundation. Waterproofing contractor after the remediation. Fixr puts basement mold at **$1,500 to $4,000**.\n\n**Everywhere at once, days or weeks after a flood or burst pipe** → restoration company, urgently, and this is the version most likely to be a live insurance claim. Fixr puts mold inside walls and drywall at **$1,000 to $12,000**. When that many trades are in play at once, [the four-vendor map](/water/who-does-what/) sets the order — and [whether to file at all](/water/call-insurance-or-not/) is worth a minute's arithmetic before you call the claims line.\n\nTiming separates the two causes people most often confuse:\n\n- **Worse in winter, on cold surfaces, no water source anywhere near it** → condensation. Heating and ventilation, not a leak hunt.\n- **Worse through humid summer months, in a basement or crawl space** → ambient humidity. A dehumidifier held around 50% relative humidity solves more of these than any contractor.\n- **Appeared within a couple of weeks of a specific water event** → that event caused it. Restoration, and tell your insurer while the connection is still obvious.\n- **Keeps returning in the same spot after you clean it** → the source is still live. Stop cleaning and start looking; you are treating the symptom on a loop.\n\nFor overall scale: Fixr puts mold remediation at **$1,500 to $9,000** with a national average of **$3,500**, or **$10 to $30 per square foot**, and an independent inspection at **$450 to $800**.\n\n## Who to call first, in order\n\n1. **The trade that owns the water source** — plumber, roofer, HVAC, waterproofer — per the section above.\n2. **An independent mold inspector**, if the growth is hidden, disputed, or you need documentation for a landlord or an insurer. Skip this if you can see it plainly and it's small — and if all you have is a musty smell and nothing visible anywhere, [check it against the other things a house smells like](/home/weird-smell/) before paying for a test.\n3. **A remediation company** to contain and remove.\n4. **The inspector again**, for a post-remediation clearance test. The same firm should not mark its own homework.\n5. **The rebuild** — drywall, paint, flooring — only after clearance.\n\nWhat each wrong order costs you:\n\n- **Remediating before the leak is fixed** is the expensive one. You pay full price for a job that reappears in the same spot within weeks, and the second quote is rarely cheaper.\n- **Hiring one company to test and to remove** hands the pricing decision to the party being paid. Get the inspection from someone with nothing to sell you.\n- **Letting the remediator run its own clearance test** leaves you with no independent evidence the job worked — which matters most in exactly the situations where you need evidence.\n- **Closing walls or painting before clearance** hides the problem rather than ending it. Paint, including \"mold-resistant\" paint, does not kill what is already growing.\n- **Scrubbing it yourself first** on anything beyond a small hard-surface patch does two things at once: it aerosolises spores into the rest of the house, and it destroys the documentation you'd want in a landlord or insurance dispute. Photograph before you touch it.\n- **Running the HVAC while you work out what to do** turns a local problem into a whole-house one.\n\n## Who will tell you this isn't their job\n\nMold sits between more trades than almost anything else in a house, and the refusals are predictable:\n\n- **Home inspectors generally won't test for mold.** It is a separate discipline and, in a number of states, a separately licensed one. You want a mold assessor or industrial hygienist.\n- **Assessors and testing labs won't remove it**, and the better ones decline on principle — the separation is the point of hiring them.\n- **Remediation companies won't fix the leak.** They're not plumbers or roofers, and many will decline to quote at all until the source is dealt with. That refusal is a good sign, not an obstacle.\n- **Duct cleaners are not remediators.** A duct cleaning is not a remediation, and no reputable duct cleaner will claim otherwise.\n- **HVAC contractors won't remediate.** They replace or clean affected components after the remediation, not instead of it.\n- **Pest control will say no.** Mold is not a pest, and this is a call people make surprisingly often. The one adjacent thing pest control does handle is the moisture-loving insects that show up alongside mold — different problem, different invoice.\n- **Painters and general handymen should decline** to paint over it. If one offers, that is the contractor to avoid.\n- **Your landlord's maintenance guy with a spray bottle of bleach is not remediation.** Bleach on porous material adds water and leaves the roots; the growth returns.\n\n## Insurance: what usually decides it\n\nCoverage follows the *cause*, not the mold. Mold that traces to a sudden, accidental, covered event — a burst pipe, an appliance failure — is generally the version insurers will engage with. Mold that traces to long-running humidity, a slow leak, or a maintenance issue is normally excluded, and many policies cap mold specifically even when they cover the underlying event. Ask your insurer what your mold limit is; it is often far below the numbers above.\n\nThe mechanism behind most denials is timing rather than the mold itself. Once a leak is characterised as gradual — something a reasonable owner would have noticed — the resulting mold is characterised the same way, and \"I didn't realize it had been leaking\" reads as confirmation rather than mitigation. Practical consequences: report the water event the day you find it, photograph the growth before anyone disturbs it, keep the plumber's or roofer's invoice showing when the source was fixed, and describe what you found and when you found it rather than speculating about how long it had been there.\n\n## If you rent\n\nPut it in writing — email or text, so it's timestamped — with photos. Most states treat significant mold as a habitability issue, making remediation the landlord's obligation and cost. If they don't act, your local health or code-enforcement department will often inspect, and that inspection report is what gives you leverage. Keep your own copies of everything; verbal complaints are worth nothing in a dispute.",
  "costs": [
    {
      "item": "Mold inspection / testing",
      "range": "$450–$800",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-inspection"
    },
    {
      "item": "Mold remediation",
      "range": "$1,500–$9,000",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    },
    {
      "item": "Mold remediation, national average",
      "range": "$1,500–$9,000 (average $3,500)",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    },
    {
      "item": "Mold remediation, by area",
      "range": "$10–$30 per sq ft",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    },
    {
      "item": "Independent mold inspection",
      "range": "$450–$800",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    },
    {
      "item": "Mold in a crawl space",
      "range": "$500–$2,000",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    },
    {
      "item": "Mold in a basement",
      "range": "$1,500–$4,000",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    },
    {
      "item": "Mold in an attic",
      "range": "$1,500–$9,000",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    },
    {
      "item": "Mold inside walls / drywall",
      "range": "$1,000–$12,000",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    },
    {
      "item": "Mold in the HVAC system",
      "range": "$3,000–$10,000",
      "source": "Fixr",
      "source_url": "https://www.fixr.com/costs/mold-remediation"
    }
  ],
  "faq": [
    {
      "q": "Is 'black mold' actually more dangerous?",
      "a": "Stachybotrys chartarum gets the headlines, but the CDC's position is that you should remove any significant indoor mold growth regardless of color or species — the health response varies by person, not neatly by species. Practically: identifying the species rarely changes what you do about it."
    },
    {
      "q": "Should I test before removing?",
      "a": "If you can see it and it's small, testing mostly buys a number. Testing genuinely helps when mold is suspected but hidden, when you need documentation for a landlord or insurance dispute, or to verify a remediation job afterward."
    },
    {
      "q": "Why shouldn't the same company test and remediate?",
      "a": "Straightforward conflict of interest — the party quoting the removal also decides how much removal you need. Independent inspection first is the standard advice, and it's also how you get a defensible post-remediation clearance test."
    },
    {
      "q": "Does insurance cover mold?",
      "a": "Typically only when it results from a covered sudden event, like a burst pipe, and many policies cap mold coverage at a few thousand dollars. Mold from long-term humidity or a leak you didn't fix is nearly always excluded."
    }
  ],
  "sources": [
    {
      "label": "EPA: Mold cleanup in your home",
      "url": "https://www.epa.gov/mold/mold-cleanup-your-home",
      "accessed": "2026-08-09"
    },
    {
      "label": "Fixr: Mold remediation cost",
      "url": "https://www.fixr.com/costs/mold-remediation",
      "accessed": "2026-08-11"
    },
    {
      "label": "Fixr: Mold inspection cost",
      "url": "https://www.fixr.com/costs/mold-inspection",
      "accessed": "2026-08-11"
    },
    {
      "label": "Fixr: Mold remediation cost",
      "url": "https://www.fixr.com/costs/mold-remediation",
      "accessed": "2026-08-10"
    }
  ],
  "updated": "2026-08-24",
  "url": "https://whodoicallfor.com/water/black-mold/",
  "json_url": "https://whodoicallfor.com/water/black-mold.json",
  "recommended_call": null
}