You’ll be surprised at all the clever places mold can grow and thrive in your home, secretly compromising your air quality and health. It’s no longer only in dark, damp common areas that you have to worry about. Some mold is growing in places you may not even think about, and the only way you know is because of strange odors that linger in your home.
To put an end to mold growing in hard-to-reach, hidden places, you must recognize this problem and start checking for it before it becomes a costly fix or a deadly health hazard. Keep reading to learn more about the unexpected places household mold may be hiding in your home.
Underneath the Carpet
Even if you are meticulous about cleaning every nook and cranny in your home regularly, mold may still be present. You may have checked and cleaned the most apparent places where mold grows in your house. However, one hidden place that most won’t think to venture is beneath the carpet. Perhaps you or a family member spilled something at some point and spot-cleaned the rug. Or maybe the subfloor beneath the carpet underlayment is growing mold due to moisture from the surface or room below, whether it’s the basement, kitchen, or bathroom. Whatever the reason, a damp microclimate may be breeding Stachybotrys, Penicillium, Cladosporium, or some other dangerous type of mold that could put your home’s structure and your family’s health in jeopardy.
Houseplant Soil

If you love to keep plants in your home all year long, you may be surprised to learn that your plant may be harboring mold in the soil. Mold may start to grow and thrive on your houseplant if you overwater it and don’t provide proper drainage. Although houseplants are a great way to keep your indoor air healthy, if the soil is contaminated with mold, it can release mold spores that can harm your health.
Washing Machine Gaskets

If you own a front-loading washing machine, you may have a mold problem brewing right beneath your nose. The thick rubber seal, known as the gasket, surrounding the door of the washing machine is a harbinger for disgusting, black mold. Since this area is often moist and occasionally warm, it is the perfect breeding ground for mold, which thrives on the old soap residue and lint that accumulate here. You’ll know that mold is present on your washing machine gasket if there is a lingering musty odor every time you open the door to wash clothes.
Behind Wallpaper
Wallpaper is making a comeback, and with its growing popularity comes the problem of mold. Many people love installing wallpaper in moisture-prone areas such as bathrooms, kitchens, or powder rooms. Vinyl wallpaper, in particular, may trap moisture that builds up in these rooms, leading to humidity or condensation. As a result, mold spores will develop and feed on the wallpaper adhesive. Signs that you may have mold growth beneath your wallpaper are an unusual musty odor or cosmetic changes to the wallpaper, such as bubbling or bulging. If you actually see mold through the wallpaper, it could mean the mold growth is so bad that it has compromised the drywall and wood behind it.
Inside Air Purifiers
Air purifiers are designed to remove pollutants floating in the air inside your home. Ironically, this gadget can become a breeding ground for mold, which can send spores spewing around your home. HEPA filters are excellent at capturing microscopic particles floating in the air, including mold spores. However, if they are placed in a high-humidity area of the home or the filter isn’t replaced regularly, mold colonies can thrive within them.
Refrigerator Drip Pans
Right behind the grill at the bottom of the refrigerator or near the compressor at the back is usually a drip pan. This is probably one of the most overlooked places where mold can grow and thrive in a home. The drip plate is designed to collect the condensation and defrost the ice from the cooling coils. The compressor’s heat is supposed to evaporate this moisture. However, when this process isn’t working correctly, it can become a breeding ground for mold and bacterial growth that you will never know is there. The only dead giveaway that there is mold growing in this area of the home is a really funky odor in your kitchen that persists no matter how much you clean.
Air Conditioner Ducts
Another way that mold may go undetected in your home is in the air conditioning ducts. Mold can grow within the ductwork, feasting on dust, dander, and other organic debris. These items, coupled with condensation, create an unhealthy amount of mold spores that are dispersed throughout the room whenever the air conditioner is in use.
Chimneys and Fireplaces
Although this area of the house is typically hot and dry, there are components that can support mold growth. The chimney flue is dark and has limited airflow when closed. Moisture from rain, snow, or condensation can get trapped here and start to grow mold. As creosote and soot accumulate, they become food sources for mold. As with mold in other places, you’ll know that it is present from a putrid odor that will come through primarily on humid or rainy days.
Window Seals and Panes
In winter, it is pretty standard to see some condensation on window panes. The cold exterior and the warm interior make condensation inevitable. However, persistent condensation, particularly within the interior of the panes of glass, isn’t normal. Trapped moisture in this part of the window can eventually increase the chances of mold growth. Seals may also attract moisture, which could lead to mold buildup. Left unchecked, mold that grows in window seals may spread to the window frames and the surrounding drywall.
Behind Tiled Walls
One of the sneakiest places in your house for mold to grow is behind tiled walls, particularly in the bathroom. It’s the sneakiest because you may never know that it is growing there at all. The porcelain or ceramic tile covering the mold monster won’t seem to give you any indication that colonies are growing beneath. However, beneath the surface of the drywall and wood behind the shower or other wet areas, some of the most significant black mold buildup in your home may be hiding. While a slightly musty smell may be present, the tile’s perfect barrier may create a facade that makes it seem all is well.

On Old Books
If you have a home library or are simply an avid book reader, you may also have mold growing on some of your old titles. Old books can be a haven for mold growth, and the glue and bindings are a delectable food source for it. If the books are stored in high-humidity areas such as basements or attics, you will start to see fuzzy growths appear on them. Unfortunately, the mold may spread from the damaged book to other perfectly normal books.
Tips on Addressing Mold in Hidden Places
While cleaning mold in the most obvious places is easy, mold in hard-to-reach, hidden areas can pose a threat to your health and indoor air quality. You must clean these areas or get the remediation needed to avoid severe damage to your home’s structure or your family’s respiratory health. Here are some ways to treat mold lurking in hidden places in your home.
DIY Cleaning
In some cases, you can fix mold issues with pantry staples. Cleaning your washing machine gasket and refrigerator drip pan may be a simple DIY weekend warrior project. A bucket of vinegar, dish soap, and water solution, along with gloves, will do the trick to eliminate mold from your washing machine gasket and refrigerator drip pan.
Remediation
Cleaning mold yourself isn’t always the best solution. While this could clean the surface, it won’t get to the heart of the mold. Also, some molds are very toxic and dangerous to try to remove on your own. Therefore, it is ideal to rely on a team of professionals to combat it. Mold behind wallpaper, behind tiled walls, and within the chimney may be best handled by a professional remediation team. Also, if it is within the HVAC system, you should let a professional handle the mold removal.
Replacement
In some instances, only replacement will work. For example, mold that has built up on your air purifier filter needs to be removed and replaced with a new one. Mold that has grown inside the window panes will require replacement windows. Also, mold that has grown beneath your carpet may require new flooring and underlayment in the affected area, or the entire carpet and underlayment may need to be replaced. Houseplants and old books may be remediated by a plant professional or a book conservator, respectively. However, if the mold is severe, you may also have to replace these items.

