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Where to Check When You Smell Mold but Do Not See Mold

Smelling mold in your house is one of the most maddening experiences a homeowner can endure. Your nose tells you something is wrong, that there is mold nearby, and you know this is a dangerous smell — a smell that means the family could get sick. The only problem is that you can't find the source of the smell!

The Most Common Places to Find Mold

Unfortunately, humans aren't bloodhounds and your nose may not necessarily be able to lead you directly to the smell. But your brain can. When you're on the hunt to sniff every single thing in your house to find the source of that elusive and alarming mold smell, we're here to help. Use the following list as a guide to help you identify all the most likely places in your home where mold might be growing and the smell might be getting in.

Underneath the Soft Furniture and Cushions

Mold loves to eat moist fabric, and water is subject to gravity. So whether your furniture was flooded or just spilled on at some point, that moisture will likely sink to the bottom and can easily start a mold colony. Check underneath your couch, heavy upholstered chairs, and around the inside and underside of any removable cushions.

Inside the Upholstery and Cushions

The mold might also be invisibly inside your upholstery where it is dark and protected. Your nose will likely tell you if there is a hidden mold colony inside a couch cushion, footstool, or an upholstered chair you are inspecting.


It's a sad but true fact that houseplants are often subject to mold because mold loves to eat organic material. Check the leaves for health and the underside of leaves where mold likes to hide. Also, turn the soil. If you find fuzzy growths that smell sour, those aren't fertilizer beads.

In the Attic, Especially Along the Roof Beams

Head up to your attic and bring a very bright light. When moisture slips in through tiny flaws in your roof, it will gather on the beams and underlayment and can begin to foster mold. Look for the signature white, brown, or green splotchy patterning and signs of decay, especially on the attic beams.

Exposed Insulation in the Attic, Garage, or Utility Closets

Now look at any visible insulation in your attic and any place in your home where insulation can be seen. Some forms of insulation are hospitable to mold and it is certainly porous enough to make a decent non-organic home.

Under-Scrubbed Surfaces Near the Stove or Microwave

We rarely think about it, but many cooking styles aerate a lot of grease and food particles which then settle on nearby kitchen surfaces. And we don't always clean every surface that accumulates this fine patina of food particles that mold happens to love to eat. Time to check all the way around your stove hood, the sides, and back of your oven, and the area around your microwave. Especially check the undersides of over-counter cabinets.

Inside the Refrigerator

Mold loves food so it's only natural that it sometimes gets into your refrigerator. Legends of pet-sized mold in office or bachelor refrigerators are familiar to us all and you might be growing a horrifying pet of your own. in particular, check the back wall, shelves, the lower drawers, and the floor of your fridge where spills can form sticky nutrient-rich puddles.

All Leftovers or Resealed Food

Any food that is a packaged leftover or with a resealed-after-opening package is suspect. Especially the bread, but really anything. Open every single package and tupperware of food in the house and give it a visual and olfactory inspection.

Under the Kitchen and Bathroom Sinks

Always check under sinks. Internal particleboard cabinetry is often unfinished, a perfect organic porous place for mold to grow. Even better if your sink drips a little bit, adding the chance of moisture to thrive on.

All Bathroom Surfaces

Any surface in your bathroom is suspect because mold, in a pinch will grow on grout and tile if there is enough condensate moisture and ambient organic material in the air.

On or Under Your Mattress

Check your mattress. We won't go into why mold loves mattresses, but it does and a moldy mattress is about the biggest hazard to your health possible.

Windowsills, Inside and Outside

Windowsills are often made of metal and experience condensate from different temperatures indoors and outdoors. A perfect combination for mold growth. Check both the inside and outside of your windowsills.

Hanging Curtains

Mold also happens to love curtains that hang undisturbed for long periods of time. Any moisture that gathers on the curtain wicks to the bottom, which can create a constant slightly-damp area of fabric that is great for mold growth but very bad for people.

Your AC Unit, Vents, and Ducts

One of the most elusive and pervasive sources of the mold smell is when it's in your air conditioning system. There could be mold growing in your air filter, in the AC unit itself, or growing in the always-slightly-moist area of your home's ventilation ducts. Or on the vent covers themselves. You may need an AC and duct cleaning service to remedy this.

Any Stored Cardboard in the Garage or Utility Areas

Mold also happens to love cardboard, especially cardboard that has been left in a not-so-protected area and has been allowed to get damp and ripply. Cardboard boxes in the garage or folded flat in your utility area are great mold habitats.

Your Washer and Unwashed Laundry

Of course, check your washing machine. If you have a new modern front-loading HE machine, the huge rubber seals can become a home for mold and they seal too tightly to air out if kept closed between loads. Weird, but true. And for good measure, check any laundry piles or hampers that may be damp and harboring mold spores.

The Carpet and Carpet Pad

If you still can't find the mold, check the floors in the rooms where you've smelled the sour tang. When a carpet or carpet pad has been soaked, it can become a medium for a mold colony out of sight but not out of smell.

Hidden Behind the Drywall

Finally, it's possible that the mold you seek can't be found in a regular homeowner search. Mold often finds a way to grow on the dark protected backside of drywall panels and will require professional remediation to get rid of. This is even more likely if you found signs of mold in several other places in your home suggesting a central colony that is constantly producing spores.

We're On Your Side

If you have identified mold in your home or still can't find the source of the mold smell, the trouble might be hidden inside your air vents, ducts, or HVAC. Contact us today for the HVAC inspection and repairs you may need to remedy the situation and free your home from that elusive musty smell.

Call (305) 805-8166 to ask how we can help.

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