Questions to ask a mold remediator before you hire

Ask these before you sign with a remediation company. There is no score to add up. A company that works carefully can usually explain what they will do and why, and put it in the written scope.

Training and years in business are a starting point, not proof of good work. Moldlist has not assessed the quality of any listed business’s work. What Moldlist checks

1. What will the written scope say before work starts?
A written scope is how you compare quotes and how you check the finished job against what was agreed.
A clear answer covers: The areas and materials involved, what will be removed and what will be cleaned, how the work area will be contained, what is excluded, the price, and what happens if more damage is found.
2. How will the water problem be fixed, and by whom?
EPA says that if you clean up mold but don’t fix the water problem, the mold will most likely come back. Cleanup alone isn’t the whole job.
A clear answer covers: Whether fixing the source is in their scope or someone else’s, and how they will confirm materials are dry before anything is closed up.
3. How will you keep mold from spreading to the rest of the home during the work?
EPA describes containment as limiting the release of mold into the air and surroundings during the work. How much a job needs depends on the job.
A clear answer covers: A plan for your home: which areas get sealed off, how the air is handled, how debris leaves the house, and how the rest of the home is protected and cleaned.
4. How do you decide what to remove and what to clean?
Killing mold is not the same as removing it. EPA says dead mold can still cause allergic reactions, and it does not recommend biocides such as bleach as a routine part of remediation.
A clear answer covers: Which materials they expect to remove and why, and how the rest will be cleaned.
5. Which products will you use, and can I see them before work starts?
You can only ask about a product, or ask for a different one, if you know what it is before it is used in your home.
A clear answer covers: The name of each product, how and where it will be applied, its safety data sheet, and time for you to review them before work begins.
6. How will we know the work is finished, and who checks it?
Agree on what “finished” means before work starts, so the check measures something specific. A check by someone with a stake in the job passing tells you less than one by someone without that stake. A completion check is about the building, not your health: NIOSH says short-term air sample results can’t be read as a health risk.
A clear answer covers: Written criteria for “finished”, agreed before work starts; who checks the work against them and how they are connected to the remediator; the documents you will receive; and what happens if the criteria aren’t met. Ask whether you can choose who does the check.
7. Do you pay referral fees or share ownership with any inspector, including the one who assessed my home?
Referral payments and shared ownership are not always disclosed. Knowing about them helps you judge both the scope and the completion check.
A clear answer covers: A direct answer, including any fee or connection with the inspector who assessed your home.
8. Who will do the work and who supervises it? What training or license do they hold?
The certificate on a website may belong to someone who won’t be at your home, and part of a job can go to subcontractors. A company’s certification or license doesn’t tell you who will work in your home. If a company won’t name its supervisor, you can’t look that person up.
A clear answer covers: The supervisor’s name, each credential they hold and who issued it, whether your state requires a license, whether subcontractors will do any of the work, and proof of insurance.

If someone in your home has CIRS or strong sensitivities

You don’t have to share a diagnosis. Describe what the people in your home need. Moldlist does not publish a list of products that are safe or unsafe for everyone. Ask the professional to tell you what they plan to use and why, and to put any changes in writing. Course completion, a certification and good field practice are separate things. Licenses, certifications, and training

9. What accommodations can you offer for the sensitivities in our home, what are their limits, and where will they be written in the scope?
Describe what the people in your home need, such as different products or extra protection for the rest of the home. You don’t have to share a diagnosis. Raising it before the scope is written makes any changes part of what you agree to.
A clear answer covers: The specific accommodations they can offer, what they can’t do and why, and where each one appears in the written scope.
10. Have you completed any training relevant to clients with CIRS or chemical sensitivities? If so, which?
Finishing a course, holding a certification and doing good work in the field are different things. A course shows someone learned the material, not how they apply it in your home.
A clear answer covers: Either a plain no, or the exact course, the organization that ran it, who on the crew completed it and when, and whether that person supervises your job. You can ask that organization to confirm it.
11. Can your crew avoid fragrances, essential oils and scented products in our home? What can’t you avoid?
Agree on this before work starts, so it is part of the written scope rather than a request on the day.
A clear answer covers: What the crew can and can’t avoid, any substitutions, and where the agreement is written in the scope.

Take the questions with you

- What will the written scope say before work starts?
- How will the water problem be fixed, and by whom?
- How will you keep mold from spreading to the rest of the home during the work?
- How do you decide what to remove and what to clean?
- Which products will you use, and can I see them before work starts?
- How will we know the work is finished, and who checks it?
- Do you pay referral fees or share ownership with any inspector, including the one who assessed my home?
- Who will do the work and who supervises it? What training or license do they hold?

If someone in your home has CIRS or strong sensitivities:
- What accommodations can you offer for the sensitivities in our home, what are their limits, and where will they be written in the scope?
- Have you completed any training relevant to clients with CIRS or chemical sensitivities? If so, which?
- Can your crew avoid fragrances, essential oils and scented products in our home? What can’t you avoid?

Find a remediation company · Questions to ask an inspector · Licenses, certifications, and training

Sources

Editorial date: October 14, 2026. No outside advisor approved this page. It is general information, not a building assessment.

1. What will the written scope say before work starts?

2. How will the water problem be fixed, and by whom?

3. How will you keep mold from spreading to the rest of the home during the work?

4. How do you decide what to remove and what to clean?

5. Which products will you use, and can I see them before work starts?

6. How will we know the work is finished, and who checks it?

7. Do you pay referral fees or share ownership with any inspector, including the one who assessed my home?

8. Who will do the work and who supervises it? What training or license do they hold?

9. What accommodations can you offer for the sensitivities in our home, what are their limits, and where will they be written in the scope?

10. Have you completed any training relevant to clients with CIRS or chemical sensitivities? If so, which?

11. Can your crew avoid fragrances, essential oils and scented products in our home? What can’t you avoid?

Take the questions with you

Sources