How to Get Rid of Mould Smell at Home: A Step-by-Step Guide

That stubborn, stale “wet” smell hanging around after rain, a closed-up weekend, or a pile of damp towels is more than just unpleasant—it’s a warning sign. Musty odours usually point to excess moisture and hidden mould or mildew, which can irritate allergies, damage surfaces, and even put your bond at risk if you’re renting. In coastal and humid parts of NSW, it’s a common headache—but it’s absolutely fixable.

The key is not to mask the smell with candles or sprays, but to remove its cause and the odour at the same time. That means hunting down moisture sources, drying spaces properly, improving ventilation, cleaning safely and thoroughly, and giving soft furnishings the deep clean they need so spores and odour molecules don’t linger.

This guide walks you through a clear, step-by-step plan: how to identify the odour, find and stop leaks and condensation, bring humidity under control, clean small mould patches safely, wash and deodorise fabrics, deep clean carpets and upholstery, use effective odour absorbers, refresh drains and appliances, maintain filters, and build simple prevention habits. We’ll also cover when to call a professional in NSW. Let’s get your home smelling fresh—and keep it that way.

Step 1. Identify the odour and assess for mould and moisture

The first move in how to get rid of mould smell is to map where it’s coming from. Musty, earthy odours usually mean moisture feeding mould. Sweep the home slowly, noting where the smell peaks and when it worsens (after rain, showers, drying laundry). This quick assessment stops you masking the problem and saves time later.

• Hotspots & clues: Under sinks, bathrooms, windowsills, wardrobes, behind furniture; look for spots, stains, peeling paint, condensation.
• Touch-test: Skirting, carpet edges, walls; lift rugs for cool/damp patches.
• Fabrics: Isolate damp towels, laundry, gym gear, pet beds to wash later.
• Humidity: Use a hygrometer; rooms above 60% need attention.

Step 2. Find and stop the moisture source (leaks, condensation, rising damp)

To truly get rid of mould smell, you must cut off the moisture that’s feeding it. Dehumidifiers help, but the priority is to locate and stop the water getting in. Work methodically from wet rooms outwards and from ceiling to floor, looking for leaks, overflows, sweating pipes and damp rising from the subfloor. Fixing the cause now prevents the odour returning and protects surfaces and furnishings.

• Fix plumbing leaks: Check under sinks, behind toilets, around dishwashers and washing machine hoses for drips or stains. Tighten connections or call a licensed plumber for repairs.
• Sort roof, gutters and downpipes: Clear blockages and look for overflow marks on eaves and walls. Book maintenance if you see sagging gutters or rusted sections.
• Seal bathrooms and showers: Re-silicone around trays, baths and basins; regrout cracked tiles to stop water tracking behind walls and into floors.
• Stop window and door ingress: Reseal frames and sills, repair cracked caulk, and check that rain isn’t blowing in around gaps.
• Tackle condensation at the source: Wrap “sweating” cold-water pipes with foam pipe insulation to reduce dripping and damp on nearby surfaces.
• Address rising damp/subfloor issues: Look for tide marks, musty skirtings or salt-like deposits. Ensure subfloor vents are clear and drainage falls away from the house; seek professional damp-proofing if it persists.
• Check appliances and drip trays: Air conditioners, fridges and dehumidifiers can leak or overflow—empty and service as needed.

Once the water source is stopped, you’re ready to ventilate and bring indoor humidity below 60% so the smell can’t rebound.

Step 3. Ventilate rooms and reduce humidity to below 60%

With the source of moisture controlled, push stale air out and keep indoor humidity under 60% so mould can’t thrive. Fresh air plus controlled drying breaks the cycle that keeps musty smells hanging around, especially in bathrooms, laundries and closed-up rooms.

• Create cross-ventilation: Open windows/doors on opposite sides to flush humid air; let in sunshine where possible.
• Use exhaust fans correctly: Run bathroom and kitchen fans during use to remove steam and cooking moisture.
• Run a dehumidifier: Set it to 55–60% RH; empty the tank and clean its filter so it works efficiently.
• Measure, don’t guess: Use a simple hygrometer to track rooms that sit above 60%.
• Improve airflow: Keep interior doors ajar, crack wardrobes, and leave a gap behind furniture near external walls.
• Limit indoor drying: Dry washing outside or use a vented dryer to avoid adding moisture back in.

Step 4. Dry out wet areas and contents quickly and safely

With the moisture source fixed, dry anything wet—fast. Musty odours persist because water sits in carpets, underlay, soft furnishings and tight corners. Move air across wet surfaces, remove trapped moisture, and use sunshine where practical. Dry first, then clean; the quicker you dry, the less chance mould has to return.

• Blot standing water: Mop hard floors and soak up puddles promptly.
• Lift rugs/carpet edges: Ventilate the underlay with spacers to release trapped damp.
• Extract, then dehumidify: Wet/dry vacuum carpets; run a dehumidifier at 55–60% RH.
• Separate soft furnishings: Remove cushions and covers; sun-dry outdoors if possible.
• Clear bathroom moisture: Squeegee showers; leave doors open and fans on until dry.

Step 5. Clean small mould patches on hard surfaces (safe DIY approach)

Once things are drying out, remove visible mould on hard, non‑porous surfaces (tiles, glass, sealed paint) so the odour can’t regenerate. Keep DIY to small areas; if growth covers over about a square metre, keeps returning, or you suspect toxic black mould, stop and call a professional. Work with good airflow and basic PPE.

1. Protect yourself: Wear gloves, a P2/N95 mask and eye protection; ventilate well.
2. Choose a cleaner: Use a 50/50 white vinegar and water mix, or 3% hydrogen peroxide. A mild bleach solution can be used on non‑porous bathroom areas. Never mix products.
3. Wet and dwell: Spray until the patch is fully wet and leave for 10–15 minutes.
4. Scrub and wipe: Agitate with a soft brush; wipe away residue with clean cloths.
5. Rinse if needed, then dry: Towel off and run fans/dehumidifier so surfaces dry quickly.
6. Dispose and inspect: Bag used wipes. Re‑grout/re‑silicone if cracks are harbouring mould.

Step 6. Wash and deodorise fabrics, bedding and towels

Textiles trap odour, so even after drying rooms, musty smells can linger in towels, bedding, curtains, gym gear and pet beds. To truly get rid of mould smell, launder anything suspect promptly. Clean the machine first, wash hot where the care label allows, use proven deodorisers, and dry completely—preferably in sunshine—so smells don’t rebound.

1. Clean the washer: Wipe drum, add a couple of tablespoons baking soda, run a hot empty cycle.
2. Boost the wash: Add 1 cup white vinegar or 1 cup baking soda to the load (hottest safe setting).
3. Pre‑soak if stubborn: 30–60 minutes in warm water with vinegar before washing.
4. Dry fully: Line‑dry outside in sun or machine‑dry until bone dry.
5. Refresh soft items: Wash pet beds and removable covers; lightly mist hard‑to‑wash fabrics with a fabric odour eliminator.
6. Prevent re‑odour: Don’t leave wet loads in the washer; hang towels to dry between uses.

Step 7. Deep clean carpets, rugs and upholstery to remove musty odours

Soft furnishings trap moisture and odour molecules deep in fibres and foam, so even a dry room can still smell musty. To truly get rid of mould smell, deep‑clean and dry these items thoroughly, then keep air moving until they’re completely dry.

• Vacuum thoroughly: Slow passes, including edges and under furniture; clean or change the vacuum filter regularly.
• Deodorise first: Sprinkle baking soda over carpets/rugs, leave 1–2 hours, then vacuum to lift embedded smells.
• Deep clean wisely: Steam clean/hot‑water extract carpets and rugs; avoid over‑wetting and speed‑dry with fans and a dehumidifier. If odours persist or there’s water damage, book a professional clean.
• Upholstery care: Wash removable covers and sun‑dry; for fixed fabric, light steam and quick drying. For leather, wipe with a mild vinegar–water solution—do not oversaturate.

Step 8. Deodorise rooms with baking soda, charcoal and other absorbers

Once moisture is under control and surfaces are clean, use passive absorbers to pull musty odours from the air. This helps finish the job when you’re working on how to get rid of mould smell without masking it. Place them close to known hotspots and refresh regularly.

• Baking soda bowls: Set out 1/2 cup in open dishes in smelly rooms/wardrobes; leave overnight and replace every few days.
• Activated charcoal bags: Position near bathrooms, laundries and carpets; use multiple small bags and follow the packet for replacement.
• Target soft zones: Slip small containers into cupboards, under sinks and behind furniture where air can stagnate.
• Quick freshen-up: Simmer white vinegar or lemon peels for 15–20 minutes to neutralise lingering odours after cleaning.
• Keep it safe: Place absorbers out of reach of children and pets, and combine with ventilation/dehumidification for best results.

Step 9. Refresh drains, appliances and bins that can harbour mould smells

Musty odours often hide in drains, wet appliances and bins. A fast refresh here removes the source, not just the smell, to get rid of mould smell. Clean with hot water and white vinegar or 3% hydrogen peroxide on non‑porous parts, then dry thoroughly.

• Drains: Flush hot water; add bicarb, then vinegar; wait, flush again.
• Dishwasher: Scrub filter and seals; run the hottest empty cycle with vinegar.
• Washing machine: Wipe door seal and dispenser; run a hot empty maintenance cycle.
• Bins/caddies: Wash, spray 50/50 vinegar–water or peroxide; sun‑dry; sprinkle baking soda.

Step 10. Replace HVAC and dehumidifier filters; consider an air purifier

Dirty filters recirculate odours and moisture‑laden dust. To get rid of mould smell, replace your HVAC/air‑con return filter and clean dehumidifier filters so airflow isn’t choked. Power off first, fit the right size, and note the change date—especially in humid months.

• Replace filters: Swap AC/HVAC filters; clean and fully dry washable types. Check monthly in damp seasons per the manufacturer.
• Consider an air purifier: It may help reduce odours and allergens; run it where smells linger and replace filters as directed.

Step 11. Use this quick room-by-room checklist to track stubborn smells

Use this quick checklist to chase down lingering musty odours room by room. Move clockwise with windows open, trust your nose, and log issues. If you’re still working out how to get rid of mould smell, this helps confirm moisture is stopped, surfaces are dry, and soft furnishings or filters aren’t re‑seeding the scent.

• Bathroom: Check fan works, grout/silicone, window sills, vanity leaks; hang mats to dry.
• Laundry: Inspect hoses, clean washer seal/dispenser, leave door ajar; dry baskets.
• Kitchen: Clear sink trap/drain, clean dishwasher filter/seal, check under‑sink leaks; wash bin.
• Bedrooms/Wardrobes: Look behind furniture, skirtings and carpet edges; dry shoes/bags; clean fabric bedheads.
• Living areas: Lift rugs/underlay, vacuum upholstery, wash pet beds; wipe window frames/condensation.
• Hall/Entry: Dry umbrellas/shoes, check door seals; sun‑dry doormats.
• AC/Dehumidifiers: Clean/replace filters; empty drip trays.
• Garage/Storage: Replace damp cardboard, air stored fabrics; ensure subfloor vents are clear.

Step 12. Keep mould smells away with simple weekly prevention habits

Now you’ve cleared the odour, lock in the win with simple weekly habits so mould and musty smells can’t regroup. These take minutes, cost little, and keep indoor humidity in check—ideal for coastal, humid NSW homes. Build them into your Saturday tidy‑up or set quick reminders.

• Ventilate daily: Open opposite windows for 10–15 minutes; let sun in.
• Use exhaust fans properly: Run during and 20 minutes after showers/cooking; squeegee tiles and glass.
• Dehumidify smartly: Keep RH at 55–60%; empty the tank and clean the filter.
• Dry laundry fast: Line‑dry outdoors or use a vented dryer; hang towels to dry between uses.
• Wipe condensation: Dry window frames/sills; leave wardrobes ajar and a gap behind furniture.
• Clean and vacuum: Weekly vacuum/mop; wash bath mats, shower curtains and pet beds.
• Refresh absorbers: Replace baking soda/charcoal; give drains and dishwasher filters a quick clean.
• Do a leak check: Look under sinks and around appliances; fix drips immediately.

Step 13. When to call a professional cleaner or remediator in NSW

Sometimes musty odours point to hidden or recurring moisture problems that DIY can’t resolve safely. In NSW, a licensed mould remediator can identify moisture pathways, remove contamination, and dry structures properly, while a professional cleaner can restore carpets, rugs and upholstery so odours don’t rebound.

• Persistent odour: Smell lingers after you’ve fixed leaks, ventilated and cleaned.
• Large or returning mould: Especially on porous materials like plasterboard or insulation.
• Health concerns: Suspected black mould or symptoms (wheezing, headaches, itchy eyes).
• Water‑damaged interiors: Soaked carpets/underlay, walls or subfloors after leaks or storms.
• Subfloor/rising damp: Ongoing damp or poor ventilation you can’t control.
• HVAC issues: Mouldy air‑con smell or filters clogging soon after replacement.

A local expert can assess, treat, and deep‑clean, giving you a dry, fresh result that lasts—particularly important for rentals and end‑of‑lease standards across NSW.

Bringing it all together

Musty odours don’t disappear by chance—they go when moisture stops, rooms dry out, and soft furnishings are properly cleaned. You’ve now got a clear plan: trace and fix the water source, ventilate and dehumidify (keep RH under 60%), dry fast, clean small mould safely, wash textiles hot, deep‑clean carpets and upholstery, refresh drains and appliances, swap filters, and lock it in with simple weekly habits.

If the smell lingers, or you’re dealing with soaked carpets, persistent stains or water‑damaged soft furnishings, professional help is worth it. For fast, thorough results across the Central Coast to Newcastle, request your free quote with SMK Carpet Cleaning and enjoy a fresher, healthier home that stays that way.