Why Does My Carpet Smell Musty? Causes and What to Do

A musty, earthy smell from carpet almost always points to one thing: moisture that isn't drying out. It's especially common in Connecticut basements, finished lower levels and rooms that stay closed up during humid summers. Here's how to find the cause and deal with it.

Common causes

• High indoor humidity. Carpet and pad absorb moisture from humid air. Basements are the usual suspects.
• A past spill or leak. A drink, a pet accident, an overflowing plant or a window leak that soaked the pad and never fully dried.
• Over-wet cleaning. Rental machines that leave carpet soaked can create a musty smell days later.
• Moisture from below. Concrete slabs in basements can wick moisture up into carpet and pad.

Step 1: Find the source

Sniff low and move around the room — the smell is usually strongest in one area. Press a paper towel into the carpet to check for dampness, and look along walls, windows and under furniture. If the smell is everywhere, humidity is the likely cause.

Step 2: Dry things out

• Run a dehumidifier. Keeping indoor humidity roughly between 30% and 50% makes it hard for musty odors and mildew to develop.
• Improve airflow with fans, and don't keep basement rooms sealed up.
• Fix any leaks before cleaning — otherwise the problem comes right back.

Step 3: Clean the carpet

Once the source is dealt with, a thorough hot water extraction can rinse out the soil and residue that hold odors. Strong extraction matters here: the goal is to remove moisture, not add more. We use a Butler truck mount with powerful suction and set up air movers so carpets dry as quickly as possible.

When carpet can't be saved

Be cautious if you see visible mold growth, if the carpet sat wet for several days, or if it was soaked by floodwater or sewage. In those cases the pad (and often the carpet) usually needs to be removed, and a water damage restoration company should assess the space. Cleaning alone isn't the right fix for contaminated water damage. For clean-water leaks that only soaked carpet or rugs, see our wet carpet cleanup.

Keep it from coming back

• Run a dehumidifier in basements from spring through fall.
• Clean up spills quickly and dry the area with a fan.
• Have carpets professionally cleaned on a regular schedule so soil and residue don't build up.

Not sure whether your carpet needs cleaning or something more? Call us — we'll give you an honest answer. Or get an instant estimate for a cleaning.