Mold inspection: what to know

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

What mold inspection is

A mold inspection looks for visible mold and the moisture sources that feed it. The inspector may take air or surface samples for laboratory analysis, then reports the findings and where the moisture is coming from. This is general information and not health advice. If you have symptoms or health concerns, speak with a doctor.

Signs you need it

  • You see dark spots, fuzzy growth or discoloration on drywall, trim, window frames or the underside of subfloors
  • There is a musty smell that returns after cleaning, especially in a basement, bathroom, crawl space or attic
  • Paint is bubbling or peeling on an exterior wall, or a wall stays damp after rain
  • A past leak, flood or plumbing failure was dried out quickly, and you are not sure the wall cavity was dried fully
  • You are buying a home with a known moisture history, and the seller's disclosure mentions water or mold

What the pro does

  • The inspector interviews you about past leaks, floods, odors and the health concerns in the household
  • They walk the home with a moisture meter and check the places water is likely to collect, such as basements, crawl spaces and bathrooms
  • They look at the attic, the ducts, the windows and the exterior for the sources of moisture and condensation
  • They take air or surface samples where the visible growth or the odor suggests a problem, and send them to a lab
  • They measure humidity and check the ventilation of the kitchen, the bath and the laundry
  • They write a report with photos, the sample results and the moisture sources that need to be fixed before cleaning

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Every job is different, so we do not publish prices.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.

  • Size of the home and the number of areas where moisture or growth is suspected
  • Number of air and surface samples taken and sent to the lab
  • Whether the inspection includes a moisture mapping of walls and floors
  • Access to crawl spaces, attics and wall cavities that need opening or camera inspection
  • Lab turnaround time when a faster result is needed
  • Whether the report includes a written scope for remediation
  • Follow-up testing after the moisture source is fixed

What a written quote should spell out

  • Areas inspected, including basements, bathrooms, crawl spaces and attics
  • Moisture readings and the method used to measure them
  • Number and type of samples taken, with the lab named
  • Lab results delivered with an explanation of what they show and do not show
  • Moisture source findings listed by location
  • Whether a post-repair test is included, and the terms for it

Questions to ask before you hire

  • What exactly will you test for, and does the lab work tell us the type of mold?
  • Which moisture sources did you find, and which are still active?
  • Do you take samples, and if so, how many and where?
  • Will the report separate what needs cleaning from what needs a moisture repair?
  • Are you licensed or certified for mold work in this state, and can I check that?
  • Do you also perform remediation, and would that be a conflict with the report?
  • Can you test again after the moisture is fixed to confirm it is dry?

Red flags

  • They say the home has a serious mold problem without taking any samples or readings
  • They push a remediation contract in the same visit and do not offer a written report
  • They recommend a fogger, a sealant or a treatment as a cure without finding the moisture source
  • They will not say what the samples do not show or what the lab tested for

What you can do yourself

You can look for visible water stains and dampness, note where and when you smell a musty odor, and check the basement, bath and crawl space for standing water or condensation. Fix a visible leak you can reach safely, such as a dripping faucet or a loose gutter, and run the exhaust fan when you shower. A small patch of surface mold on a hard surface can often be cleaned by the owner with detergent and water, gloves and a mask, but do not cut out or scrub a large area or hidden growth, because that can spread spores. Call an inspector for the findings and a remediation contractor for large or hidden growth or any removal.

Licenses and permits

Mold inspection is commonly done by licensed or certified professionals, and some states require a specific license or accreditation for mold assessment. Check with your state licensing agency and your local health or building office for the rules that apply to mold work in your area.

Mold inspection questions

Does a mold inspection tell me if the air is safe?

The inspection shows what was found in the areas tested on the day. It does not clear the whole home or give health advice. Ask the inspector what the samples do and do not show, and speak with a doctor about health concerns.

Do I need air samples or is a visual check enough?

A visual check finds visible growth and moisture. Samples can help when growth is hidden, when the odor is strong without visible growth, or when a buyer or a landlord needs documentation. Ask the inspector which fits your situation.

Should the same company inspect and remediate?

Many people prefer separate companies, so the findings are not shaped by the job that follows. Ask whether the inspector also does remediation and how they manage that conflict in the report.

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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