Musty smell in the house: how to track down the source

You walk in after a weekend away and the house smells like an old basement, or a closet smells stale no matter how often you wash what's in it. A musty smell is the most common way people around Little Rock first find out they have mold in the house, usually before they see any. The smell comes from mold and bacteria growing on something damp. Find the damp, and you've found the problem.

What the smell is telling you

The EPA says you may suspect hidden mold when a building smells moldy but you can't see the source. Its list of usual hiding places: the back of drywall, wallpaper or paneling, the top of ceiling tiles, the underside of carpet and pad, inside walls around leaking or sweating pipes, wall surfaces behind furniture where condensation forms, inside ductwork, and roof materials above the ceiling. Nearly every one of those comes back to a leak, a sweating surface or air that stays too humid.

Where to look in a Little Rock house

When the smell is strongest is the best clue. Pay attention for a few days, then start with the matching row:

Little Rock's climate tilts the odds toward the first two rows. Morning humidity outside averages in the high 80s through the summer months, and dew points near 70°F mean any cool surface under or inside the house can get wet (see the numbers by month).

Checks you can do yourself

• Buy a hygrometer. EPA notes a humidity meter costs about $10 to $50 at a hardware store. Its target is indoor humidity below 60 percent, ideally 30 to 50. Leave one in the problem room for a few days, and another in the crawl space in July if you can get to it.
• Look for condensation. Water beading on windows, walls or cold-water pipes is a sign the air is too humid, and EPA says to dry it and deal with the source quickly. Rust on pipes or vents is a sign it's been happening for a while.
• Use a flashlight, not a hammer. Look under sinks, around the water heater, at ceiling corners and in the attic over bathrooms. EPA warns that pulling off wallpaper or opening walls with mold behind them can release a large burst of spores, so if you suspect it's inside a wall, stop and get it inspected.
• Check the AC drain. EPA's prevention list includes keeping air conditioning drip pans clean and drain lines flowing. If the pan at the air handler has standing water, that alone can explain the smell.

Mold in an apartment or rental house

Renters can't open walls or crawl under the house, so the job is documenting it. Report the smell or any leak to the landlord in writing, with dated photos, and keep a copy. The Arkansas Department of Health says there is no state or federal law requiring property owners to remediate mold. Arkansas's 2021 habitability law (Act 1052) does require a functioning roof and building envelope, plumbing that meets code, and working heat and air if the unit came with it, for leases signed or renewed after November 1, 2021. As a Mitchell Williams law firm summary describes it, the tenant gives written notice, the landlord has 30 days to fix the problem, and if it isn't fixed the tenant's remedy is ending the lease; rent can't be withheld. A leaking roof or a broken AC drain behind the smell falls under that; mold on its own isn't named. This isn't legal advice, so read your lease and talk to a lawyer if it gets that far. Landlords: a musty unit is usually cheaper to inspect now than to gut after a summer. More on rentals in mold in Jacksonville rental homes.

When to call someone

Bring in a pro if the smell stays after you've dried things out and humidity is under control, if you've found growth bigger than about 10 square feet, if it's coming from inside a wall, ceiling or the ductwork, or if someone in the house has asthma or other health concerns. A mold inspection in Little Rock should look for the moisture source with a meter, not just take air samples, and if growth turns up, mold remediation in Little Rock covers what a proper cleanup involves. Call and we'll connect you with a local mold professional who serves your town.