Where Does Mold Grow? Here Are 15 Places To Check for Mold Growth

Mold grows anywhere with moisture present. In particular, mold can be found in the shower, under carpets, in your washing machine, and even in your mattress. Most mold is relatively harmless. However, it should be removed, and preventative action should be taken immediately to prevent further spread.

Where does mold grow? The better question may be, where doesn’t mold grow?

Mold is a common nuisance and potential health risk, and it can grow in any number of places. Since mold can spread in as little as 48 hours under the right conditions, it’s important to know where mold typically grows so steps can be taken to remove the mold right away.

From where people sleep to where they eat, mold can spring up anywhere and anytime. All it takes is moisture and a bit of time for mold spores to take hold. Here are some of the top places mold can grow.

1. Kitchen

In residential spaces, the kitchen has two factors that encourage mold growth: water and rarely cleaned dark areas. Make sure the kitchen doesn’t turn into a breeding ground for mold spores by checking the following areas:

• Refrigerator drip pans: The drip pan is located underneath your refrigerator. It is designed to collect water that results when your refrigerator goes through its normal defrost cycle or when water drips from condensation coils. Because they’re out of sight, drip pans are easy to forget about. The combination of moisture and their location makes them a potential breeding ground for mold spores. Depending on your make and model or refrigerator, some drip pans can be pulled out, while others may require some disassembly to access.
• Around the dishwasher: Even a small leak around your dishwasher can create a major mold problem. If there are signs of a dishwasher flooding or any moisture around the base of the dishwasher, call an appliance repair specialist immediately. The inside of the dishwasher is also at risk of growing mold if used infrequently, as it contains both moisture and food remnants.
• Under the sink: Leaks from water pipes or garbage disposals may be easier to detect, but even moisture from wet sponges can create enough humidity for mold spores to take hold.

2. Living Room and Den

We don’t usually think of the living room as a prime place for mold to grow, but there are several places worth checking.

• Window sills: The combination of exposure to condensation, poor air circulation, and dirt can create ideal conditions for mold around windows and doors. It’s important to ensure windows and doors are properly sealed to reduce the amount of condensation that can develop during extreme weather.
• Carpets: People might think carpets only get moldy if they get wet, but moisture from concrete floors or wet crawl spaces can work its way into a carpet and encourage mold growth.
• Behind furniture: Furniture that is positioned against the wall may cause mold to grow on the walls or the furniture itself due to humidity and lack of ventilation. Bookcases, in particular, can cause mold to grow if there’s moisture present.

3. Bedroom

Mold in the bedroom can be particularly detrimental to your health, so it’s important to know where to look for it.

• Mattress: Certain types of mattresses, such as memory foam, can retain moisture in particularly humid environments or if the person tends to sweat at night. If the bed or room itself is not well-ventilated, then mold can grow.
• Windows: Similar to window sills in living rooms, mold can grow along windows, especially if they are improperly sealed or left open often, letting moisture in.
• Vents: Excess moisture can develop in vents, which are prime areas for mold growth.

4. Utility Room

These rooms are often small with minimal natural light and poor ventilation, making them one of mold’s favorite places to grow.

• Washing machine: Front-loading, high-efficiency washers are great, but they’re also notorious for having a musty odor because of mold growth. It’s beneficial to periodically check and clean around the door and seal on your front-load washer to keep mold from developing.
• Water heater: Traditional tank water heaters are often placed in areas that are already at risk for mold growth: closets, attics, or utility rooms. With drip pans or slow water heater leaks, it's a recipe for the development of mold.
• Wallpaper: It may seem strange, but mold can grow under wallpaper in rooms with high humidity and poor air circulation. The best way to avoid this kind of mold growth is to remove the wallpaper and use mold-resistant paint instead.
• Floor mats: Because mats are typically used to remove mud and moisture from shoes, they also create a hospitable environment for mold spores to grow. Remove, rinse, and let floor mats air dry periodically to keep them free from mold.

5. Bathroom

While bathrooms usually have overhead exhaust fans, they’re still typically not well-ventilated. That, coupled with frequent moisture and warm temperatures, can lead to mold growth. Here are some common places mold can grow in the bathroom.

• Shower and bathtub: Because showers and baths are used frequently, they often won’t dry fully between uses, making them an ideal place for mold to grow.
• Sink: Similar to the shower, sinks are used frequently and, therefore, stay moist, which can cause mold to grow.
• Toilet: Toilets will often form condensation, which can lead to mold growth, particularly behind the toilet and in the tank.
• Walls and floor: Because of the repeated moisture and warm temperatures in bathrooms, the walls and floor may be susceptible to mold growth. This is especially true if you have wallpaper in your bathroom. Mold can also develop behind walls when the drywall or tile is damaged or compromised.
• Toothbrush holder: A glass or ceramic holder is a convenient spot to store a toothbrush. However, it’s also a perfect habitat for mold, thriving on the water that drips from the toothbrush into the container.

To keep mold from developing in these areas, try to keep them as dry as possible and clean them regularly with a disinfectant.

6. HVAC Systems

Heating, ventilation, and air conditioning (HVAC) systems are all prone to moisture and condensation, which can cause mold to develop.

• Window air conditioners: Window units suck in dirt and pollen from outside, providing mold with its favorite material in which to grow. If the AC sits without use for long periods, it’s even more likely to grow mold.
• HVAC ductwork: The heating and air conditioning system has multiple components that are conducive to mold growth. During the summer season, the air coming in has a high moisture level, which can condense and accumulate in the duct lining material. Any leak in the ductwork allows moist air to escape into the unconditioned spaces. The inside of the ductwork can also develop mold as well.

7. Floors

It can be difficult to find mold under carpet or floorboards. Carpet provides a nourishing environment for molds because it captures dirt. Floods, leaks, and spills can soak carpet through to the padding and subfloor. Carpet also absorbs the moisture in the air.

If you’ve experienced or suspect a leak, make sure to check under the carpet padding and subfloor for early signs of mold. After a flood, consider checking under floorboards by cutting a small hole about every 24 inches. Use a flashlight and mirror to look for mold underneath the floor. If cutting the floor is not an option, a moisture detection device can be used, or a professional service to determine the amount of damage to the subfloor. While the initial costs and inconvenience are a consideration, preventing mold from developing mitigates any costs and inconvenience.

8. Appliances

Machines that use water or create moisture in some form can facilitate mold growth and mildew. On a washer, the rubber piece that goes around the door, called the washer boot, may have mold behind the flap. Most refrigerators have a drain pan underneath the appliance that catches the condensation from the freezer defrost drain. The kick plate may have to be removed to access the pan, which can contain water and mold.

9. Offices

Mold can grow in the usual places in an office, such as on window sills or behind furniture, but paper can be a particularly appealing material for mold to eat.

• Filing cabinets: Since paper is made from wood pulp, it holds moisture for a long time. Especially in humid areas, paper files can become damp and give mold a dark place to grow.

10. Basement or Crawl Space

Full of dark and potentially damp corners, basements and crawl spaces can be breeding grounds for mold spores. Keep an eye out for leaks in the foundation, as well as any moisture around windows and piping.

11. Attic

The attic is another area that attracts moisture. Because attics provide ventilation for buildings, if mold develops there, it can quickly spread to the rest of the house. Mold can be found in attic walls, in insulation, near windows, in vents, in the foundation, and behind any equipment such as the furnace.

12. Indoor Plants

Overwatered plants are the ideal spot for mold to grow. Prevent mold from growing on indoor plants by ensuring that they have proper drainage, aren’t watered too frequently or too much, and that humidity is monitored.

13. Fireplaces and Chimneys

In properties with a fireplace, water from rain and snow can drip down your chimney. The porous bricks and mortar absorb it and give mold a place to grow, especially in the spring and summer when the fireplace isn’t being used.

14. Garages

Garages can develop mold for several reasons. Vehicles coming in and out, sometimes with moisture and other debris on them, can cause mold to grow. Additionally, the large garage door opening and closing can allow moisture to get in or cause leaks.

15. Water Damaged Areas

One of the most common places mold will grow is where there’s water damage. If there’s been flooding or a leak, the mess needs to be cleaned up and repairs done quickly to ensure there’s no more water leaking into the area, risking mold growth. Depending on the extent of the water damage, you may need to hire a professional to clean up and restore the damaged area to ensure mold does not develop.

What Is Mold?

Formed by certain types of fungus, mold can be found anywhere with moisture and oxygen. While mold is an important part of the ecosystem, helping to break down organic matter in nature, it’s not something you want to find in your home or business.

There are many different types of mold that have a wide range of appearances and impacts on our health. Mold typically falls into one of three categories:

• Allergenic: These types of mold may cause allergic reactions, such as sneezing and congestion, but are otherwise harmless.
• Pathogenic: These types of mold can cause issues in individuals with certain health conditions.
• Toxigenic: These types of mold create their own toxins and are, therefore, quite dangerous and can lead to serious health complications from exposure.

How Does Mold Grow?

Mold spreads through mold spores, which are microscopic, airborne mold cells. While mold spores are generally invisible to the naked eye, they are present both indoors and outdoors. The mold then grows and becomes visible when the spores land on a surface with moisture and/or other organic material to digest.

Mold Growth FAQ

Finding mold in a home or business can be overwhelming. Here are some commonly asked questions about mold.

Where Is Mold Most Likely To Grow?

Mold is most likely to grow in damp and poorly ventilated areas. In any building, this means that the bathroom and kitchen are highly susceptible to mold, as well as around any windows and doors. Places like a basement or attic are also prone to mold. Mold can also grow anywhere that there’s been a leak or flood.

How Does Mold Affect People?

Aside from being a nuisance, mold can also be a health hazard. Mold exposure can cause mild, allergy-like symptoms such as watery eyes, runny nose, sneezing, itching, and coughing. In more serious cases, mold exposure can cause headaches, dizziness, and difficulty breathing.

How Do You Keep Mold Out of Buildings?

Preventing mold growth starts with limiting the accumulation of moisture and addressing the issues that could lead to mold growth. Fix any leaks quickly and take proactive steps if you experience a flood or water damage. If mold is present, consider hiring a restoration professional to help with mold remediation.

What Should Someone Do If They Find Mold In Their Property?

While many DIY methods exist online, it’s best to hire a professional if you find mold in your home or business. Contact Rainbow Restoration for help with mold removal and remediation.

What Attracts Mold?

Mold is attracted to moisture. Mold feeds on organic materials, so it can grow on something like wood or paper if there’s enough moisture. If left unchecked, mold will grow quickly and continue to spread.

Find Mold? Call Mold Removal Professionals

So, where does mold grow? The short answer: everywhere. No matter how it’s discovered, finding mold in a home or business can be a troubling experience. DIY mold removal is almost always ineffective and comes with inherent risks.

To ensure mold problems are handled properly, call the mold remediation specialists at your local Rainbow Restoration®. We’ll seal off the mold-affected areas, control the humidity, safely remove the mold, and clean up afterward. When the job is complete, we’ll communicate what caused the mold and explain how to prevent it from coming back.

To learn more about our services, contact Rainbow Restoration’s mold removal team and breathe easy again.

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This article is intended for general informational purposes only and may not be applicable to every situation. You are responsible for determining the proper course of action for your property. Services should be performed by licensed and experienced professionals. Rainbow Restoration is not responsible for any damages that occur as a result of this blog content or your actions. For the most accurate guidance, contact a Rainbow Restoration professional for a custom, on-site assessment.