Mould on furniture is usually caused by excess moisture, high indoor humidity, and poor ventilation. Mould spores are always present in the air, but they only begin to grow when they land on a damp surface that provides a food source—like timber, fabric, or leather—especially when the relative humidity stays above 60%.
Picture this: a timber dresser placed against a cool, exterior wall in a basement or garage. With limited airflow and a cooler wall surface, warm indoor air condenses, creating hidden moisture behind the furniture. This damp pocket becomes the perfect breeding ground for mould, even if the rest of the house feels dry.
Australian mould guidelines recommend keeping indoor humidity levels below 50% to help prevent growth.
What Does Mould Look Like on Furniture?
Mould can appear in many different forms depending on the surface and species. Here’s what to look for:
| Furniture Material | Common Mould Appearance |
| Wooden Furniture | Fuzzy, powdery, or slimy patches in shades of black, green, or blue-green (such as Cladosporium or Aspergillus). Sometimes it looks like light grey or white film (mildew). It may also seep into the timber grain as blotchy stains. |
| Upholstered Furniture (Couches, Chairs) | Small fuzzy spots or discoloured patches in black, green, or pink. The smell is a giveaway — a strong, musty odour usually means mould is hiding deep inside cushions or foam. |
Even if you can’t see it, a persistent musty smell is a clear sign that mould is present.
Why Is There Mould on My Couch?
Mould on your couch almost always means there’s too much moisture in or around it. Upholstered furniture is particularly vulnerable because its fabric and foam absorb humidity easily.
Common causes include:
- High Humidity: Humid summer weather or damp rooms allow moisture to linger in fabric.
- Water Damage: Leaks, flooding, or slow seepage through walls or windows can saturate the frame or foam.
- Poor Airflow: Furniture placed tight against walls can trap moisture behind it.
- Spills: Even small spills can leave enough moisture for mould to form if not fully dried.
How to Remove Mould from Wooden Furniture
If caught early, solid timber furniture can often be cleaned and saved. Always work outside or in a well-ventilated area, and wear gloves, a mask, and eye protection.
1. Prep and Dry
Move the furniture outdoors on a sunny day. Use a stiff brush to scrub off visible mould and dispose of debris immediately.
2. Vacuum
Use a vacuum with a HEPA filter to remove loose mould spores from crevices.
3. Clean with a Mould Treatment Solution
Choose one of these:
- White Vinegar: Wipe down with undiluted white vinegar. Let it sit for about an hour, then wipe with a clean cloth.
- Bleach Solution (for raw timber only): Mix ½ cup of bleach per 4 litres of water. Test first on a hidden area. Wipe gently and allow to dry.
- Commercial Cleaner: Use an anti-microbial mould cleaner designed for timber surfaces, following instructions carefully.
4. Dry Thoroughly
Air dry completely in the sun or in a dry, well-ventilated space for several days. Sunlight helps kill remaining spores.
5. Refinish if Needed
If stains remain, lightly sand and reapply a finish or sealant to protect against future moisture.
How to Remove Mould from a Couch
If the mould has spread deeply into the foam or there’s a strong odour, it’s often best to dispose of the item, as complete cleaning may not be possible or safe.
For mild, surface-level mould:
1. Prep and Vacuum
Take the couch outside. Use a HEPA vacuum to remove loose spores from the surface. Don’t vacuum indoors, as this can spread spores around your home.
2. Treat the Area (Choose One)
- Rubbing Alcohol: Dampen a cloth with rubbing alcohol and blot the mould. It evaporates quickly and prevents further moisture build-up.
- Vinegar Solution: Mix equal parts white vinegar and water in a spray bottle. Mist the affected area and leave for 10–15 minutes before wiping clean.
- Hydrogen Peroxide: Spray a 3% solution, wait a few minutes, and blot dry. Test a hidden spot first — it may lighten some fabrics.
3. Dry Completely
Ensure the couch dries fully. Place it in a sunny, airy spot and use a fan to circulate air until completely dry.
Preventing Future Mould Growth
The best defence against mould is moisture control.
- Manage Humidity: Keep indoor humidity between 30% and 50%. Use a dehumidifier in damp rooms or during humid months.
- Improve Airflow: Leave space (about 5–10 cm) between furniture and walls.
- Ventilation: Use exhaust fans in bathrooms, laundries, and kitchens to release moist air outside.
- Fix Leaks Quickly: Repair plumbing or roof leaks immediately and dry wet materials within 24–48 hours.
- Natural Light: Sunlight helps inhibit mould growth — let light into your rooms whenever possible.
Final Thoughts
When choosing furniture, consider how materials interact with moisture. Non-porous materials like metal, sealed timber, and plastic are the most mould-resistant.
For wooden pieces, a high-quality seal or finish is key — it prevents moisture absorption and protects the surface from spores.
Ultimately, the best way to keep mould away from your furniture is to maintain good ventilation, proper humidity levels, and prompt cleaning whenever moisture appears.
Keep your home dry, bright, and fresh — and your furniture will stay beautiful for years to come.
