Mold remediation: what to know

What the job involves, what changes the price, and what to ask a pro.

What mold remediation is

Mold remediation removes mold from affected materials by containing the area, using air filtration, cleaning or discarding contaminated items, and fixing the moisture source so the growth does not return. It is specialized work. Disturbing mold can spread spores through the home, so this job belongs with a qualified remediation contractor.

Signs you need it

  • A mold inspection found growth on drywall, framing, insulation or subfloor, and the report recommends removal
  • Visible growth covers an area of a wall, a ceiling or a floor, or it keeps coming back after cleaning
  • Growth is inside a wall, under flooring or in an attic, where the source must be opened and dried
  • Water damage from a flood, a burst pipe or a roof leak was not dried fast enough, and growth has appeared
  • A musty odor persists in a room even though the visible growth has been removed by someone else

What the pro does

  • The contractor confirms the moisture source and fixes it, or arranges for the source to be fixed before removal starts
  • They set up containment with sealed barriers and negative air pressure so spores do not move into other rooms
  • They remove the contaminated materials, such as drywall, insulation or flooring, and bag and seal them for disposal
  • They clean the framing and the surviving surfaces with approved methods, and use air filtration throughout
  • They dry the structure to a level the moisture meter confirms before any new material goes up
  • They prepare the area for rebuilding, and provide documentation of the work and the post-work testing when included

What changes the price

Every job is different, so we do not publish prices. These are the things that move the quote up or down.

  • Area of growth and the number of rooms or wall cavities affected
  • Depth of the problem, such as surface growth versus growth inside framing or insulation
  • Moisture source repair needed, such as a roof, plumbing or grading fix, which is priced separately
  • Containment and negative air setup required for the affected area
  • Materials that must be removed and replaced, such as drywall, flooring, cabinets or insulation
  • Post-remediation testing and clearance sampling, if included
  • Access and the number of phases needed to keep the home usable

What a written quote should spell out

  • Affected areas listed by room, with the materials to be removed and the materials to be cleaned
  • Containment method, negative air setup and the air filtration used
  • Moisture source repair included or listed separately, and who performs it
  • Disposal method for contaminated materials and the route they will take out of the home
  • Drying method and the moisture target the structure must reach before rebuilding
  • Post-remediation testing, clearance and the documents delivered at the end

Questions to ask before you hire

  • Did you confirm the moisture source, and is it fixed or will it be fixed as part of this job?
  • How will you contain the work area, and what happens to the air in the rest of the home?
  • Which materials will be removed, and which will be cleaned and kept?
  • What drying target will you use, and how will you confirm the structure is dry?
  • Do you provide a clearance or a post-remediation test, and who performs it?
  • Does this state require a license or certification for mold remediation, and can I check yours with the state board?
  • What is the warranty on the work, and does it cover the same area returning?

Red flags

  • They start removing material without setting up containment or any negative air
  • They use bleach or a fogger to treat the growth without removing the contaminated material or fixing the moisture
  • They do not confirm or fix the moisture source before rebuilding
  • They say no testing or documentation is needed after the work

What you can do yourself

Do not attempt remediation of large or hidden growth yourself. Removing or cleaning it releases spores into the air and can spread the problem to other rooms, and disposing of contaminated materials requires care. A small patch of surface mold on a hard surface can often be cleaned by the owner. You can keep the affected area closed off from the rest of the house, report the moisture problem to the landlord or the insurer if you rent, and document the growth with dated photos. Call a licensed mold remediation contractor for the work itself.

Licenses and permits

Mold remediation is commonly done by licensed or certified contractors, and some states require a specific license or accreditation for remediation work. Check with your state licensing agency and your local health or building office for the rules that apply to the work and to disposal of contaminated materials.

Mold remediation questions

Can I clean mold off the wall myself?

A small patch on a hard surface can often be cleaned with detergent and water, gloves and a mask, once the moisture source is fixed. For a larger area, growth inside a wall or contaminated water, cleaning disturbs the growth and can release spores into the air. A remediation contractor sets up containment, removes or cleans the material safely and fixes the source of the moisture.

Why does mold keep coming back after cleaning?

Usually because the moisture source was not fixed or the structure was not dried. Ask the contractor how the source will be found and fixed, and how the structure will be dried before rebuilding.

Will my insurance cover mold removal?

It depends on the policy and the cause of the moisture. Ask your insurer what the policy covers and what documentation it requires, and keep the inspection report and the photos.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

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