Mold remediation costs range from $500–$1,500 for a small contained area to $15,000–$30,000+ for extensive structural involvement. IICRC S520 defines the standard. Containment, HEPA air filtration, affected material removal, antimicrobial treatment, and clearance testing all drive the line items. This calculator helps you build a defensible quote that passes inspector review.
Critical containment (poly barriers, zipper doors, negative air pressure): $500–$1,500 to set up depending on size. HEPA air scrubber: $100–$175/day per unit. A 200 sq ft contained area typically needs one air scrubber running for 2–5 days. Negative air creates pressure differential that protects unaffected areas — document setup with photos for the clearance inspector and any insurance file.
Mold-affected drywall removal: $2–$4/sq ft including bagging and disposal. Insulation removal (affected cavity): $2–$5/sq ft. HEPA vacuuming of framing and surfaces: $1–$2/sq ft. Antimicrobial treatment (spray application): $0.40–$0.80/sq ft per coat; encapsulant for porous wood framing: $0.60–$1.20/sq ft. Soda blasting for structural wood (studs, joists): $3–$8/sq ft — effective but slower than HEPA vacuum alone.
Clearance air sampling by a third-party industrial hygienist (IH): $300–$700 for a typical residential job. Never skip third-party clearance — it's your liability shield if the customer reports recurrence. Post-remediation verification by the same IH who wrote the protocol builds client trust and protects you legally. Include clearance testing cost in your quote as a separate line item, not buried in overhead.
Mold always has a moisture source — finding and fixing it is part of a complete remediation. If you can identify the source (roof leak, plumbing leak, condensation), include it in your scope or document that it was excluded. Reconstruction after remediation (new drywall, insulation, paint) is often an equal or larger cost than the remediation itself. Price reconstruction as a separate phase with a separate contract if you do both.