Finding the right remediation company can be overwhelming. If you were to call five different remediation companies, chances are you would get five different answers on how best to remove mold, microbial growth, and any damaged building materials. 

You can’t always count on the remediation company you hired to have obtained certain certifications or be legally required to follow a certain set of standards or procedures. 

Because laws vary widely by state, it always important to thoroughly vet any remediation company you are planning to hire. (You can learn more about the individual laws in your state by going to our Policy and Advocacy page here.

There are a lot of practices that pass as “remediation” that don’t fully address the root of the problem, which wastes your time, money, and puts your health at risk.  

Remember, mold remediation is not about killing, fogging, or painting over mold and water damage. It is about removing mold, water damage, and any other contamination safely in order to return your home’s indoor environment to a healthy state.

To help you find the right remediation company for your next project, we’ve provided some sample questions below to assist you in the vetting process. 

  1. What standards or protocols do you follow?
    • Mold remediation in the United States in not uniformly regulated. There are no federally mandated standards. This means a wide range of practices can be considered remediation. At a minimum, we recommend that remediation companies follow the standards laid out by the ANSI/IICRC S520 which are “based on reliable remediation and restoration principles, research and practical experience, and attempts to combine essential academic principles with practical elements of water damage restoration for technicians facing “real-life” mold remediation challenges.”  
  1. Will you follow the protocol and recommendations written by a third-party company like an Indoor Environmental Professional (I.E.P.)?
  • The answer should be “yes.” At this point you would have had a thorough inspection by your I.E.P. and have gone over the results, what they mean for you and your family, and the overall recommendations. It’s important that you and your I.E.P. understand the costs that are associated with the work so that in the event you can’t afford every recommendation, a plan to make the most of your investment is clearly outlined. The I.E.P.’s report should clearly outline the scope of work for to the remediation company. These recommendations should be based on what is best for you and your home, not what is fastest, cheapest, or easiest for the remediation company. 

(To learn more about the role of an I.E.P. and what a good inspection looks like, be sure check out our articles here and here.)

  1. What general steps do you follow for a typical remediation project?

IMPORTANT NOTE: No two remediation projects are the same. This description below is an overview of key components, not a detailed or step-by-step description. Please always consult with your I.E.P. who will provide guidance on the best approach for your specific situation. 

  • After taking steps to protect the other areas of the home, the first step typically involves setting up proper engineering controls which include building containment and establishing proper pressure (for more details, see the explanation in Question #4). The purpose of these engineering controls is to minimize the further spread of mold spores or contaminants into general living areas of the home while remediation is being performed. Containment should be as small as possible but as large as needed. This should include covering all supply and return events to prevent cross contamination. All workers should wear personal protective equipment (PPE). This means protection from head to toe (for more details, see explanation in Question #5).  If a company won’t invest in keeping their workers safe, chances are they won’t keep you or you or home safe either. 

    Once the environment and workers are protected, demolition begins. Materials should be removed a minimum of 18 inches (or other number determined by your IEP or remediation company) beyond any visible or known water damage or mold. Impacted materials are removed safely (see Question #7 for more detail). Any materials that remain (i.e. support beams, wood framing, etc.) are HEPA vacuumed, damp wiped, and if needed, the appropriate abrasive measure is used to remove mold roots that may have grown into the building materials. Examples of abrasive measures include wire brushing and HEPA sanding. The area is then HEPA vacuumed again. Avoid companies who don’t properly remove mold from structural components and simply spray them with harsh chemicals.

    Finally, the entire area inside containment (such as ceilings, walls, and floors) is cleaned by HEPA vacuuming, damp wiping, and HEPA vacuuming again. This is a meticulous and time-consuming part of the process as the goal is to remove any contamination that may have settled on the surface. Every surface inside the containment should be cleaned following this procedure. Do not hire a company who skips this step. 
    Per the ANSI/IICRC S520 you do not need to rely on harsh chemicals or encapsulants. The solution for damp wiping should contain a surfactant or detergent designed to remove surface dirt and mold. Any cleaning agents, antimicrobials, encapsulates, etc., should be approved by the client ahead of time. (See Question #6). 
    Once the steps above are completed, containment remains up and air scrubbers run for a predetermined amount of time prior to post remediation verification (testing) being performed. As a reminder, post remediation verification should be completed by a third party (like your I.E.P.), not your remediation company.

IMPORTANT NOTE: You must correct the moisture source that allowed for the mold growth to begin in the first place. If you don’t, your problem is likely to return. 

  1. How do you protect the home and occupants from cross contamination?
    • Proper engineering controls are an important part of the remediation process because they minimize the spread of spores and contamination into other parts of the home. Setting up proper containment around the area to be remediated provides a critical barrier between the area to be remediated and the rest of the home. Typically, containment is built with 6ml plastic and will run floor to ceiling. There should be no gaps or tears in containment. A second decontamination chamber is typically built off the main containment. 

      Proper containment alone won’t stop 100% of spores from entering the home so it must be combined with proper pressure. A HEPA-filtered Air Filtration Device (AFD), also known as an air scrubber, is converted into a negative air machine (NAM). Typically, but not always, projects require negative pressure to be established inside the containment. The pressure should be monitored continually throughout the remediation project using a tool like a manometer or other measure. Typically, containment should be under -5 Pascals or more of negative air pressure. Be sure to ask how the remediation company monitors air pressure. Additionally, equipment should be cleaned between each job to limit cross contamination from one job to another. 

      Additional measures include setting up procedures to enter and exit the containment in a way that minimizes the spread of spores from people, equipment, and bagged materials.  Ideally, the homeowner or occupant should not be living in the home during remediation. If the home has an HVAC system and ductwork, measures should be taken to clean and protect the unit and ductwork.

  1. How do you protect your workers?
    • Protecting workers is a critical part of the process. If a company doesn’t invest in keeping its worker’s safe, chances are they won’t keep you and your home safe. Workers should be in full Personal Protective Equipment (PPE) which includes full body protective suits (with a hood and booties), eye protection, gloves, and a properly working and designed respirator.
  1. What chemicals and solutions do you use in the process?
    • Any chemicals, cleaning agents or solutions should be approved ahead of time by the client. Always ask to see the Material Safety Data (MSDS) sheet of any product. Harsh chemicals are rarely needed. Any antimicrobials should be nontoxic, low odor, and environmentally friendly. 
  1. How do you dispose of contaminated material?
    • Any bags should be sealed using the gooseneck technique. The bags are then moved to the decontamination chamber where the exterior of the bags is either cleaned or double bagged prior to it be taken out of the home. Additionally, building a corridor to move people, materials, and equipment in and out of the containment safely may be needed. This will reduce cross contamination to the rest of the home. 
  1.  Do you document your work? 
    • Since the homeowner or occupant should not be present during remediation, it’s a good idea to have your remediation company document their work. This can be particularly important for legal and insurance cases.
  1.  Do you guarantee your work? What happens if my Indoor Environmental Professional does not pass the job?
    • The company should guarantee their work. You, your I.E.P., and the remediation company should agree ahead of time in writing what post testing results will mean the job has “passed.” It should be written into the contract that if the I.E.P. fails the post-remediation verification, the remediation company will come to address the issues at no additional cost to the client (you).
  1.  Have you worked on projects that have involved the removal of the contaminants listed in the I.E.P’s report?
    • Mold remediation is a very complex task on its own, but just because a company has performed mold remediation in the past does not mean they know how to remove other contaminants. For example, if your home tested positive for mycotoxins, they should be able to provide references to previous clients they have helped remove mycotoxins from their home or building.

A few important reminders as you start the vetting process:

  • Get quotes from at least three different companies.
  • Don’t forget to ask for certifications and references.
  • Ask for proof that they are properly insured (this means pollution liability as well as general liability and workers compensation). A company that uses cheaper office or janitorial workers compensation insurance policies isn’t providing proper protection for their workers working inside your home, and -- in the event a worker gets hurt inside your home -- will not provide adequate coverage for you and your family. 
  • Read every part of the contract – especially the fine print. Do not rely on verbal, email, or text agreements. Everything should be in writing: this includes the exact procedures, materials, equipment, and scope of work to be performed. 

Additional resources on remediation:

A few highlights from the ANSI/IICRC S520 on why physical mold removal is preferred over other practices (spraying, bleaching, encapsulating, fogging, etc.):

  • “Physically removing mold contamination is the primary means of remediation. Mold contamination should be physically removed from the structure, systems and contents…. Attempts to kill, encapsulate or inhibit mold instead of proper source removal generally are not adequate.” [Section 4.4 – Principles Of Mold Remediation; page 18]
  • “Source removal of mold contamination should always be the primary means of remediation. Indiscriminate use of antimicrobials, coatings, sealants, and cleaning chemicals is not recommended.”[Section 5.8.1 – Chemicals (Antimicrobials & Biocides); page 20]
  • “Using antimicrobials, fungicidal coatings, mold-resistant coatings, or sealants… during mold remediation as a substitute for proper source removal is discouraged. If [they are used], remediators should apply them after completion of remediation, and after completion of post-remediation verification, when necessary.” [Section 12.2.9 – Clean-Up; page 50]