Does Mold Remediation Prevent Future Mold?

Jun 9, 2020

The short answer to this question is no. Mold can come back after remediation. Unfortunately, even if you’ve had a lot of repairs, remediation work, clean up, and testing, you may still need more mold remediation in the future. This blog post will discuss why mold may come back after remediation was completed. 

Mold Remediation: Source, Source, Source

Mold problems inside a property vary.  One situation could involve a small amount of superficial mold growth on bathroom tile while another could be substantial mold growth throughout an entire room. These two situations will require different degrees of remediation. One may just be a simple job that calls for cleaning and the other may be more destructive and call for removing drywall or sanding plywood. Prior to removing the mold no matter the extent, it is crucial that the root cause of the mold growth is identified. Doing remediation without fixing the underlying cause is a “band-aid solution” that will allow the mold to come right back. The source could be a broken exhaust fan that isn’t removing excess humidity from a bathroom or a window with incorrect flashing that allows water intrusion during a rainstorm.  Whatever the cause may be, it needs to be addressed as part of remediation, or else mold will come back. To learn more about mold remediation check out the EPA’s website.

Multiple Sources

At times, clients are aware of a particular problem in their property.  They may call us to write a remediation protocol for the top floor of their property after a roof leak was repaired. We will gladly inspect this area only and write a remediation plan, however, it may be wise to also have the rest of the home inspected. On several occasions, we’ve had clients call us back out because of undiscovered water-related issues in areas of the property outside of the original scope of our inspection. There may be a humidity issue in the basement that is causing mold to grow on personal belongings or a leaky toilet on a different floor. It is disheartening for a property owner to complete the repairs in one area of the home, only to find that a separate area also needs some remediation and repair work.  Also, it is usually financially more prudent to fix these issues all at once versus having multiple visits and assessments completed. 

Clearance Testing for Mold Remediation

The purpose of clearance testing or post-remediation verification is to ensure that the remediation work was successful– no visible mold, dampness or elevated levels of airborne mold should be present (link to past blog).  Clearance testing usually calls for a mold air sample in a different location away from the area that was remediated. It’s a bad surprise to property owners if air samples outside of the remediation area reveal high levels of mold.  The levels may be due to cross-contamination from the remediated area or other mold problems that exist. This is why we recommend having a consultant perform an initial inspection of the entire property prior to doing any remediation and perform clearance testing after the remediation. An initial inspection can ensure that all problem areas are discovered and addressed, while clearance testing can provide peace of mind that the remediation work was successful.


The indoor environment changes over time. Building materials may become compromised, storms happen, plumbing leaks — these are just a few examples of problems that may occur. When there are water-related problems in a property, it changes the indoor environment. If you addressed a mold problem in your property and had a successful clearance test, that does not protect you from future mold problems. Things change. The key is to keep tabs of your property, ensuring that water-related problems are addressed immediately and the root cause of visible mold growth is identified and repaired. Mold isn’t like asbestos; after abatement, it can come back!