10 Unexpected Places Where Mold Creeps into your Home

10/3/2022 (Permalink)

The Smith’s didn’t notice the mold and mildew smell in their home until they came home from vacation.

“What’s that smell?” John asked.
“Mildew. Maybe mold. Maybe I left some clothes in the washer,” Kathy said.

After an hour-long search, the couple couldn’t find a leak. So they called John’s brother David — a plumber. He came right over.

“The number one rule for checking for mold and mildew?” David said, “If it uses water, chances are it’s going to leak.”

These are 10 places many homeowners overlook when checking for mold:

Dishwasher

Unless a dishwasher stops working or needs replacing or servicing, most of us don’t think about it as a potential source for mold. There are two connections under each dishwasher that have the potential for mold and mildew to get started–the water supply and the discharge connection. The water supply needs to be lubricated with the right sealant and properly tightened  periodically. The discharge connection involves a rubber hose and clamp, and installing the hose before the dishwasher is installed ensures it is done properly. Hoses wear out over time. If you’re buying an older house, it doesn’t hurt to check the dishwasher connections — especially if there’s an odd smell when you open the door.

Icemaker Connections

Refrigerators often get moved, either for cleaning or other projects. This can weaken or break the water line connection to the ice maker, causing leaks behind the refrigerator.

“It seems like a simple job, so in the real world the plumbing contractor doesn’t install the water line, another contractor does,” Hoffman said. “The connection is a compression fitting and it must be installed properly to ensure there are no leaks.”

Washing Machine Connections

When installing a washing machine, always install a brand new washing machine hose, using the rubber washers the manufacturer recommends. Also, use Teflon tape and make sure to tighten the connection with vice grips so there are no drips or leaks. After all, it doesn’t take many drips to create an environment for mold.

Hot Water Heater

“Many states have laws regarding the installation of hot water heaters, and most of them involve overflow pans that are piped to drain outside the house. The pan must be tilted ¼ inch to ensure the water does drain. Newer heaters with quick connect connectors should be properly lubricated and tightened so the shut-off valve doesn’t leak,” Hoffman said.

Plastic P-Traps

Under every sink in your home is a “P-Trap,” almost always made of PVC pipe, which expands, and contracts. This process eventually loosens the connection and allows water to leak onto the base of the cabinet. If you look under sinks in every room you’ll easily spot the stains and discoloration commonly caused by leaking P-Traps. Use Teflon tape to seal every P-Trap and check them periodically, tightening them by hand to ensure their connections don’t loosen and leak. Over tightening PVC can cause it to crack, so be careful.

Toilet Connections

“I’m amazed at how many steps the DIY home improvement shows leave out when they explain about how to install a toilet,” Hoffman said. “The base of the toilet is where most mold grows. Toilets should be installed with a horned wax ring, and then the base of the toilet grouted in with tile grout,” he said. “The grout serves as a filler between the bowl and the floor to keep the bowl from rocking. Rocking bowls are the number one reason for the wax ring being compromised, which then allows mold to get a foothold.”

Shower Doors

Shower doors should probably be installed by plumbing contractors, Hoffman said. “They know how to keep them from leaking.” Mold growing at the base of the tub may be from leaking or improperly installed shower doors. Shower doors need caulking on all three rails — the two side rails as well as the bottom rail.

Tub

A properly caulked tub isn’t just nicer looking. It keeps water and moisture from dripping down under the tub and causing mold issues. Slab floors can create more problems — especially if installed by a DIY’er. The hole(s) in concrete slabs under tubs should be filled with a liquid tar, or expandable foam insulation to ensure moisture does not wick up from the ground through the slab.

Exterior Hose Bib

If you have a home, you have an exterior hose bib — a place where the water connection sticks out from the house. If you’ve used a hose, you know a poor connection or missing rubber washer, or loose hose can result in water spraying the house. This uncontrolled spray allows water to enter the space between the sidings, or into the wall, leading to mold growth. Make sure all holes, gaps and areas around every outdoor water connection are properly caulked and sealed.

Outdoor Water Sprinklers

Siding is engineered to shed rain falling down, not sprinklers shooting water up. Make sure your sprinklers are well away from the house when turned on. If you have children or teens that are watering the yard or garden, make sure they know not to spray the house with the hose. If power washing your home, hire a professional, or take care that water is not forced up under the siding as you wash.

As a homeowner, if you take the appropriate precautions and are vigilant about upkeep, you should be able to avoid mold, or catch it at it’s outset. While mold can be a huge problem in homes, even causing health issues, it is easily preventable.