Musty Smell in the House: Causes and Solutions

You know that moment when you walk through your front door and instead of thinking “ahh, home,” you think… wait. What is that smell?

It’s not strong. It’s not obvious. It’s just… there. A faint, stubborn, slightly stale smell hangs in the air refusing to go away. You light a candle. Still there. Open a window. Still there. Deep cleaning the kitchen at 9 pm like a detective on a mission. Still. There.

It’s frustrating—and weirdly personal. Like your house knows something you don’t. Sounds familiar? We see you.

Getting rid of that mysterious, musty odour in your house? Consider it handled. Dive in.

Ways to get rid of musty smell in the house

To get rid of the musty smell in your house, you want to change the conditions that allow it to exist in the first place. If moisture and stagnant air created the odour, then they have to be dealt with first. Everything else supports that.

• Start with airflow – Dead air hangs around when it has no exit route. Pop windows open whenever you can—even a brief rush of outside air transforms a room instantly. Run extractor fans in kitchen and bathroom environments to extract moisture directly from the source before it spreads. And don’t sleep on those hermetically-sealed, forgotten spaces: lower-level basements, uppermost lofts, ghost-town spare rooms. When air flow completely bypasses these zones, dampness anchors itself down and starts building a home.
• Address what’s holding the smell – Curtains, carpets, rugs, mattresses, upholstered furniture—they absorb dampness and slowly leak odours back into the room. Wash whatever can handle it. Steam-clean where it makes sense. Wipe hard surfaces to clear away dust and bacteria feeding that stagnant note. Regularity beats aggressive one-time efforts here.
• Look at your air systems – Ventilation systems and HVAC machinery don’t simply circulate oxygen—they’re recycling whatever contaminated inventory is camping out in their internal passages. When dust buildup and random debris take over residence, they’re effectively broadcasting damp, stagnant air on permanent rotation throughout your living space. Keep filters fresh on a dependable timeline, call in professionals when units need attention, and legitimately weigh getting expert duct cleaning services if that smell is showing zero signs of surrender.
• Reduce humidity directly – Dehumidifiers dramatically lower interior moisture levels, starving dampness of conditions it requires. Neutralising sprays or absorbent powders address fabrics and surfaces harbouring scent molecules, breaking down the chemical culprits behind mustiness.
• Deal with visible mould immediately – Even if mould isn’t playing the lead role in your odour drama, any spots you can actually see deserve immediate, thorough eradication to stop mould growth from metastasising across surfaces. Apply purpose-built cleaning solutions with care and precision—amateur hour could make things exponentially worse.
• Investigate concealed water sources – If that smell won’t quit even after serious cleaning efforts and upgraded ventilation, odds are you’ve got covert dampness lurking in the walls, nested under the flooring, or absorbed into insulation material. Persistent smells often point to something concealed. A slow leak, trapped dampness, poor insulation. You name it.
• Maintain dryness in vulnerable areas – Routinely dry windowsills, shower tiles, and condensation-gathering surfaces. Prevention is quieter than repair, and far more effective at that.

Clear air isn’t created in one step. It’s the result of steady adjustments that make your home less welcoming to moisture and to the smells that tag along.

Getting rid of musty smells in the house naturally

Nature has a few tricks up its sleeve to help you get rid of a musty smell in the house, but you need to know exactly what it can offer. The below natural techniques work really well when paired with consistent cleaning.

Let’s find out the various options for a homemade musty odour eliminator and how they work:

• Baking soda – More than a cookie ingredient. Place bowls in closets or corners, let them sit for a few days, and watch them draw stale odours straight out of the air. Carpets and upholstery? Sprinkle it on, wait, then vacuum. It doesn’t just cover the smell, either. It invites it to leave.
• White vinegar – The low-key neutraliser. Spritz a diluted blend over walls, shelves, or counters. The vinegar odour evaporates, taking that lingering stale smell right along for the ride.
• Activated charcoal – Moisture’s natural nemesis. Place bags or loose charcoal near vents, inside cupboards, or anywhere air stagnates. It doesn’t scream for attention. It quietly draws dampness and odours away, month after month.
• Coffee grounds – Yes, your morning fuel doubles as a subtle deodoriser. Bowls of fresh or spent grounds in corners or closets absorb smells while leaving a gentle, energising aroma in their wake.
• Houseplants – Natural air purifiers. Peace lilies, Boston ferns, English ivy, spider plants—they do more than look pretty. They pull in humidity and filter some airborne pollutants, upgrading air quality while bringing greenery indoors.
• Essential oils and natural infusions – If you want fragrance minus the artificial component, diffuse tea tree, eucalyptus, lemon, or lavender. Let citrus peels or herbs simmer away on your stovetop. You get a gentle reset of the room’s vibe, plus the bonus of breathing in a genuinely pleasant scent.
• Sunlight and fresh air – The simplest alchemy. Open curtains. Hang fabrics outside.

What causes a house to have a musty smell?

So, why does your house smell musty? The truth is that stubborn fragrance is the aftermath of lingering dampness, air that’s basically holding its breath, and regular household materials gradually absorbing every bit of it.

Wooden surfaces, fabrics, accumulated dust—they begin their slow unraveling, releasing that stagnant aroma as they go.

The kicker? You could be gazing directly at the culprit yet perceive nothing whatsoever—no fungal growth, no telltale staining, no warning signs of any kind.

Nine times out of ten, whatever’s causing this is hiding in locations you wouldn’t think to investigate in a million years—like the hollow guts of your walls, the mysterious void beneath your flooring, or those bizarrely-angled nooks your house seems to have spawned just to mess with you.

Time to decode exactly what’s fermenting in those shadows to cook up that unmistakable odour:

• Humidity – When the atmosphere’s practically drowning in moisture, your home morphs into the ultimate odour detention centre. That’s when your curtains, furniture coverings, and that fitted carpeting start soaking up every trace of moisture. They appear completely dry to the naked eye, yet apply firm pressure and you’ll sense that hidden moisture lurking within. And the second that moisture gets locked in? You’ve essentially rolled out the red carpet for bacteria colonies and microscopic fungi to throw a house party, and their eventual byproduct is precisely that flat, soil-scented smell you don’t want.
• Water leaks – Even barely-there, undercover leaks can manufacture outsized problems. A gradual drip hiding under your basin, nested behind the washing machine, or trickling somewhere in your walls can stay completely off your radar for months. The water itself usually evaporates or gets absorbed without a trace. The problem lies in whatever materials are catching it. They maintain just enough dampness to produce that signature musty vibe.
• Ventilation. Some spaces in your home are absolute pros at hoarding stagnant air: underground basements, enclosed bathrooms, laundry chambers, tucked-away lofts. That’s simply because they don’t see any fresh air. Steam billowing from your shower or humidity escaping your washer? It sticks around indefinitely. The consequence: a heavy, motionless environment that, with enough time marinating, absorbs that trademark musty character you’d recognise anywhere.
• Building materials – Your brick, wood framing, drywall panels, and insulation batting are all acting like compact moisture traps. If they never catch a break to properly dry themselves out—particularly in vintage homes or when the weather’s throwing endless rain at you—they cling to that wetness stubbornly and leak a continuous, dirt-tinged odour that colonises every inch of your space.
• Old carpets and soft furnishings – Your carpets, rugs, mattresses, and cushioned furniture collect dust, moisture, and bits of organic material over the years—it’s unavoidable. Even serious cleaning can’t reach everything, and those buried particles keep decomposing in there, sustaining that smell long after you’ve moved on to other things.
• Vents and air systems – Your heating and cooling system, vents, and fans can easily turn into a delivery service for stagnant, moisture-heavy air throughout your entire house. Dust particles, lint clumps, and miscellaneous debris gather in those ducts, mix with ambient humidity, and when that equipment fires up, the odour spreads itself systematically into every space you’ve got.

Does a musty smell in a house necessarily mean mould?

Not particularly.

That faint, cellar-like scent isn’t always a warning sign of something spreading behind the walls. Often, it’s simply stagnant air and lingering humidity reshaping your space.

Air that doesn’t circulate changes how everything inside the room behaves, so the house smells musty with no visible mould.

When moisture hangs around, ordinary materials stop being neutral. Wood swells slightly. Plaster holds onto dampness. Carpets and upholstery act like slow-release sponges.

They don’t drip or even stain. They just retain—and then subtly exhale—that flat, stale note you keep noticing.

Even dust has a role to play. Microscopic particles and bacteria woven into fabrics generate similar odours without a single visible patch of mould in sight.

That said, the smell is still a signal. It’s not proof of mould. True. But it is proof of conditions that mould would appreciate. And that’s reason enough to pay attention.

Signs to look for

The question now is how do you find the source of that musty smell in your house? Well, moisture rarely announces itself loudly. Luckily, though, it leaves clues.

The first sign to watch for is water staining—those amber or brown marks ghosting across ceilings, tracking down walls, or hovering near windows and pipe fixtures.

Even when the surface seems perfectly dry today, the narrative underneath could be telling something else entirely. Materials retain moisture well beyond when the leak actually stopped, locking in both the visual evidence and that persistent smell.

Then there’s subtle distortion. Floorboards that lift just slightly. Doors that begin to stick for no clear reason. Skirting boards that no longer sit flush. Dampness doesn’t always flood, sometimes it slowly reshapes.

Walls tend to reveal more than we expect, too. Paint that peels. Plaster that bubbles. Uneven patches of colour that weren’t there before. All clear signs of trapped moisture.

Windows offer their own signal. If condensation is rolling out the welcome mat for you most mornings (windows obscured by fog, droplets congregating on indoor surfaces), it’s generally broadcasting that humidity is completely trapped with zero exit strategy and no dissipation options.

And lastly, pay close attention to the atmospheric vibe of certain areas. Below-ground basements, sealed-off bathrooms, closed cupboards, tight architectural corners suffering from airflow starvation—these spaces are basically engineered for this exact scenario.

If they always feel tacky or possess that eerie frozen-air quality, that’s your red flag right there.

Measures to keep musty smells away

Victory—you’ve obliterated that musty situation! But without locking in a few solid habits, that smell can creep back in unannounced, especially during humid Aussie summers.

• Put the detective hat on – Start with seasonal inspections looking for dampness indicators across your property. Keep tabs on gutters, roofing, and pipes every few months. Zero in on the typical troublemakers: basements, lofts, bathrooms, and laundry areas.
• Control indoor humidity – Running a dehumidifier in problem areas stops moisture from creeping in. Also, remember to seal gaps around windows and doors to keep cold, humid air from triggering condensation buildup. Insulation or thermal barriers turn chilly or clammy rooms into dry, less hospitable spaces for musty air.
• Keep the air moving – Moving air is your secret weapon. Pop windows open routinely—even quick bursts count—to give your dwelling a chance to inhale properly. Switch on exhaust fans whenever you’re whipping up meals or running hot showers. Never leave spaces locked down and forgotten for extended stretches.
• Mind your soft furnishings – Because they soak up moisture, dust, and debris that gradually create smells, don’t neglect cleaning them on a regular basis.
• Take care of air ducts and vents – Dirty systems redistribute damp, stale air across your home. Clean them regularly, or all your hard work is just moving the smell around instead of eliminating it.

Takeaways