Ten Unexpected Places in Your House to Check for Mold

Although mold isn't quite as dangerous as some folks might lead you to believe (especially mold remediation companies), it can still make you pretty sick-plus it looks ugly, smells bad, and can cause a lot of expensive damage to your house. If you spot mold growing somewhere in your house, you deal with it pronto-by cleaning where you can, replacing mold-infested stuff like drywall, and figuring out where the moisture mold needs to live is coming from.

But being proactive when you see mold only works if you, you know, see the mold. Mold is like any other living creature: It's tricky, and finds a way to survive and thrive when you're not paying attention. In other words, mold doesn't only grow on walls and ceilings in big, ugly patches you can't help but notice (and deal with). It also grows in some unexpected places, areas of your house you don't normally look at closely or spend time in. If you want to be sure that there's no mold lurking in your house, check these ten spots.

Floors

You might be walking on mold every day and not even know it. Mold can grow on top of your wood floors (laminate floors, too), causing discoloration, stains, and visible mold blooms-and it can also grow under your floor, on top of the subfloor it was installed over, in which case you probably won't see any visible signs until it's really out of control.

You'll also need to check under any rugs and carpet, because mold can thrive under there for a long time before you notice. Moving and cleaning under area rugs is easy enough, but you probably aren't going to be pulling up your carpet every few weeks, so check for visual and olfactory signs of mold growing in or under your carpet. Dealing with mold on your flooring probably requires bringing in professionals, because treating the problem can be very challenging, involving removing the floor and cleaning the subfloor, and if you do it incorrectly the mold will just grow back.

Water pipes

Mold needs a few things to survive-oxygen, food, and water. There's plenty of water in your home's plumbing, of course, but there's no air, usually, so mold can't grow there easily. But mold can get into your home's water system via well or city water supplies; it can grow inside water softener or filtration systems; and it can grow inside the ends of pipes and faucets where there is access to oxygen.

If you think you smell mold when you turn on your faucets, you probably are. And if you have recurring mold growth around faucets, shower heads, and toilets, that might indicate that the mold is being introduced via your plumbing. You can treat mold inside faucets and drains with vinegar and baking soda (make sure the vinegar won't harm your finishes, though), and if a filter or softener is the culprit, replacing them will probably solve the problem.

Vents and ducts

Your HVAC ducts can be a ripe breeding ground for mold, and the stuff can grow in there for a long time before it becomes noticeable. The same can be said for vents leading to the exterior of the house-the exposure to humidity and rain from the outside can eventually lead to mold growth, and if the range hood above your stove isn't vented outside, it might be blowing moist, warm air onto your kitchen cabinets, causing mold to grow.

The good news is that mold in your ducts makes itself known by its smell-every time your air conditioner or heater kicks on, you'll get a whiff of mold. The other good news is that these surfaces are fairly easy to clean-scrubbing down vents is as easy as removing them, wiping them down, and replacing them, and ducts can be sanitized with bleach and a vacuum equipped with a HEPA filter.

Chimneys & fireplaces

Mold can easily grow in your fireplace or chimney, especially if your chimney's waterproofing has failed (or wasn't installed correctly in the first place). Even a minor leak in the chimney creates the ideal conditions for mold-moist, warm, and dark.

Unless you perform a regular inspection of your chimney (which you probably should), your first sign of mold in your chimney or fireplace will be the smell. If you detect mold in there, you'll probably need to have a professional chimney sweep come out to clean it-and you should also have the chimney inspected and possibly repaired. If there's a leak, the mold will just come back-and your chimney may eventually fail altogether.

Books

If your house has high humidity (above 60%) everything inside it is at risk for mold-including your books. Books provide an ideal food source for mold, and unless you go through your library every day they tend to sit undisturbed on shelves for long periods of time-periods when mold can gleefully grow in peace. If you notice any sort of fuzzy growth, stains, or white, stringy stuff on your books, it's probably mold.

If your books are moldy, you'll have a hard time saving them. You can brush or vacuum away obvious mold, then wipe covers gently with denatured alcohol. Pages can be wiped down, too, with a sheet of wax paper between pages-just be very careful. It's a tedious job with a high chance of damaging the books further.

Wallpaper

The moment you smell mold in the house, the ceilings and walls will be your first target. An investigation will often turn up a spot of water damage that has led to a mold invasion, then the dual fun of figuring out a water leak and getting rid of the mold begins.

Sometimes the mold is hiding behind wallpaper. Mold can grow between your walls and the wallpaper in perfect safety, unseen. If you smell mold but can't find it, you can look for some subtle signs that it's lurking behind the wallpaper:

1. Discoloration. If sections of the wallpaper have become discolored or stained, that might indicate mold.

2. Damp areas. Are there slimy or greasy spots on your wallpaper? That might be the result of mold's squishy influence.

3. Peeling. Peeling wallpaper might not be due to age-it might be the mold eating away at the glue.

If you find mold behind your wallpaper, you'll need to remove it, treat your walls, and then replace it with new wallpaper-or some other wall covering.

Closets

If your closet is packed with clothes, chances are you're not seeing all of your outfits on a regular basis. If you're smelling mold in there, it's time for a thorough inspection, because a humid closet is a perfect mold-growing area. If it's on the walls or ceiling of your closet, chances are it has migrated to your clothes, bags, and shoes as well.

You can effectively remove mold from your clothing by going outside and brushing off visible mold, then either having it dry cleaned (make sure you inform your dry cleaner of the problem) or by washing it in hot water with either bleach or a sanitizer. Once that's done, it's time to figure out why your closet is so humid in the first place.

Houseplants

Your houseplants are another unexpected target for mold-but it makes sense. They tend to be damp, especially if you overwater or the pots have poor drainage, and there's plenty of organic matter to feed the mold. Dealing with moldy houseplants is easy, though-scrape it off (or replace the soil completely) and deal with your drainage or humidity issues.

Washing machines and dishwashers

Any time you combine water and heat, mold is a possibility. So it's no surprise that washing machines, dryers, and dishwashers can often become little self-contained mold farms, with the added bonus of infusing all of your clothes and dishes with that terrific mold scent.

Aside from the smell, you can look for visible signs of mold inside your washer, dryer, or dishwasher-especially behind the rubber gasket that seals the door. Mold growing back there can be very hard to see unless you dig in there to check. Cleaning out the mold is relatively straightforward: Clean off any visible mold using bleach and hot water, then run a cycle on the hottest water setting. Let it dry and you should be good to go.

Insulation

We rarely see the insulation in our homes-it's hidden inside the walls, under the floor, and in the attic space. Mold can grow well on many different types of insulation in your house, making it very hard to discover. Your best course of action is to check all the unseen spaces in your house at least once a year, and put eyes on your insulation as much as you can. You probably don't want to open up the walls just to check the insulation, of course, but you can usually visually inspect attic, basement, and crawl space insulation pretty easily.

If you find mold, you're going to have to have all the insulation removed, perform a deep clean of any surfaces where mold has taken root, and replace the insulation-and find a way to control the humidity levels or eliminate water leaks.