Mold and mildew are fungi that can lead to health issues and make your facility appear dirty

Mold and mildew create an instant “ick” factor in any facility. In addition, inhaling or touching mold can cause allergic reactions or trigger asthma episodes in people with asthma1. Mold and mildew can cause problems for anyone, and allergies to mold are common. It is important to understand what mold and mildew are, how to prevent their growth, and how to treat problems as they arise.

Mold and mildew are both types of fungi, but there are some key differences2:

  • Mildew is a type of mold but can only grow on the surfaces of materials (such as grout, glass, and tile). Mildew doesn’t grow inside surfaces, and it is much easier to clean than mold. Mildew can be removed with the right cleaning product. Products that say they are mildewstatic can also help prevent mildew from returning.
  • Mold is a fungus that can cause health issues, and allergies to mold are common. Unlike mildew, mold can grow inside structures and porous surfaces like walls and can be harder to remove. Mold on surfaces can be removed like mildew, but mold in walls or in other porous surfaces may require special treatment or even removal and replacement of materials.

In cases where mold and mildew are already present, a disinfectant that kills mold may be necessary to prevent the issue from recurring or spreading. Cleaning may remove the stains and immediate visible mold and mildew but may not be enough to kill the mold and mildew-causing organisms.

Damp, dusty and dirty areas help mold and mildew thrive

Mold and mildew will grow where areas are damp or wet3. The dampness can be in the air from humidity, or on surfaces from leaks or improper drying. In a recent study by the EPA, they found that 85% of US buildings had been exposed to water damage, which means that 85% of buildings in the US may be at high risk of mold problems4. Molds do not need a lot of water to grow; water left from a shower or humidity in the air may be enough. In addition to moisture, mold and mildew need food. If surfaces are dirty, dusty, or greasy, these can be food for mold4. Mold and mildew can thrive in cool and warm temperatures.

Based on these factors, molds and mildew tend to grow well in these areas3,5:

BathroomWater and humidity from showers, and soap scum residue on surfaces provide a great place for mold and mildew
KitchensGrease and food messes can feed mold and mildew
Basements and Crawl SpacesCooler temperatures, dampness, dirt and higher likelihood of flooding make these likely spots for mold and mildew
AtticsRoof leaks, dust in attics, and warmth in the summer

Preventing mold and mildew is easier than treating mold and mildew

The best treatment for mold and mildew is to prevent it. Follow these tips to prevent and handle small mold and mildew problems6.

  • Before mold appears: Keep humidity in rooms low with appropriate air exchange through HVAC systems. In some climates, you may need dehumidifiers. Keep HVAC filters clean and change regularly. Regularly clean and wipe surfaces dry.
  • When you notice some mold or mildew: Use a product designed to kill mold and remove mildew. You can find this information on the product label. Clean the mold and mildew from the surface according to the product instructions. Thoroughly dry the surface after cleaning and removing the mold. Dispose of cloths or towels used to clean the surface to prevent spreading the mold and mildew to other areas.
  • After a flood or leak: Thoroughly dry all wet areas with fans. If small areas of mold are present, clean and dry thoroughly. If there is a musty smell after drying, this could indicate a more serious mold issue and you should consult a professional.

Prevent, treat, repeat: Keep mold out of your facility

Mold problems cease to be small when they recur frequently or cover more than 10 square feet of area. Mold is not an issue to ignore. Not all mold problems can be dealt with on your own. For serious, spreading, or recurring mold issues, you may want to consult with a remediation expert. If mold remediation is necessary, it can be extremely expensive: it can cost up to $25 per square foot, and potentially more if fixtures need to be replaced or if a complete remodel is required7. To avoid such expensive remediation, we recommend a prevent, treat, repeat pattern of dealing with mold issues when they first arise.

  • Prevent mold and mildew by keeping areas and surfaces dry. You can also help prevent mold and mildew by treating areas with a product that can prevent the growth of mold and mildew.
  • Treat mold as it arises with a disinfectant with claims against mold and mildew (not just mold and mildew stains – look for a product that can actually kill mold).

Together, these tips can help protect your facility from mold problems.


1. Environmental Protection Agency. (n.d.). Mold and Health. EPA.
2. LLC, P. (n.d.). Mold vs. mildew: What’s the difference? (everything you need to know). Mold vs. Mildew: What’s the Difference? (Everything You Need to Know).
3. Environmental Protection Agency. (n.d.-b). Mold Course Chapter 1. EPA.
4. Environmental Protection Agency. (n.d.-c). Summarized Data of the Building Assessment Survey and Evaluation Study. EPA.
5. LLC, P. (n.d.-a). 9 common causes of mildew in your home (& how to prevent it). 9 Common Causes of Mildew in Your Home (& How to Prevent it).
6. Centers for Disease Control and Prevention. (2022, November 14). Homeowner’s and Renter’s Guide to Mold cleanup after disasters. Centers for Disease Control and Prevention.
7. Gerhardt, N. (2023, March 3). How much does mold remediation and removal cost?. Forbes.