Why is my furniture going mouldy? Causes and fixes
Why furniture goes mouldy
Furniture goes mouldy when it stays damp for long enough, and that usually comes down to where it stands. Push a wardrobe, sofa, bookcase or headboard tight against an outside wall and you create a thin pocket of still air against the coldest surface in the room. Moisture from the room condenses on that wall, the back of the furniture stays damp, and mould grows on both. The piece itself is rarely the cause; the room's humidity and the lack of air moving around it are.
That's why the first thing to do when you find mould on furniture is to pull it out and look at the wall behind. If the wall is spotted or damp too, cleaning the furniture is only half the job.
Where to look
- The backs and undersides of wardrobes, chests of drawers and bookcases on outside walls.
- The back and base of sofas and armchairs, and the underside of seat cushions.
- Headboards and bed bases, especially solid divans.
- Drawer interiors and the bottoms of cupboards, where the air never moves.
- Anything kept in a closed spare room, storeroom or garage.
In Cyprus, furniture is most at risk in homes shut up for months, older ground-floor flats with damp walls, and bedrooms warmed in winter with a portable gas heater, which adds water vapour to the air as it burns.
Cleaning mould off wooden furniture
Light mould on sealed, varnished or painted wood usually wipes off. Take the piece outside or open the windows, and wear gloves and a mask. Don't brush the mould off dry, which spreads spores. Wipe it with a cloth wrung out in a mould cleaner, working gently and keeping the wood damp rather than wet: soaking makes timber swell and can lift veneer. Don't mix cleaning products, and test the cleaner on a hidden area first if the finish is delicate. Then let the piece dry thoroughly in an airy room before it goes back, with a gap from the wall this time.
Bare or waxed wood is more porous, so mould can settle into the grain. After cleaning, a light sanding outdoors, with your mask on, can take out remaining marks, and the surface can then be resealed. Antique or valuable pieces are better handed to a furniture restorer.
Wooden floors, skirting boards and frames
Wood that is fixed to the building goes mouldy for the same reasons, but you can't carry it into fresh air, so the source needs more attention. Clean and dry the surface in the same way, then work out why it was wet. On ground floors, mould along the bottom of skirting boards is often a sign of damp rising through the wall, and painting over it won't hold. Wooden window frames and sills that blacken each winter are catching condensation running off the glass, which our guide to mould around windows in Cyprus homes explains. Wooden floors that darken at the edges, start to cup or feel soft underfoot may be sitting on a damp slab or above a leak. In each case, the wood will keep going mouldy until the moisture is dealt with.
When mould has gone too deep
Surface cleaning has limits. Wood that feels soft or spongy when pressed, crumbles at the edges, is stained right through, or grows mould again soon after cleaning has taken water deep into the grain, and the mould has followed it. Veneer that has lifted and chipboard that has swollen won't recover. For ordinary furniture, that usually means replacing the piece or the affected panel.
Structural timber is a different matter. Mould on roof timbers, beams or joists points to a moisture problem in the building itself, and timber that stays wet can weaken over time. Don't scrape or sand it yourself; have it assessed professionally. If the growth is in the roof, see mould in the attic or roof space. Where timber is affected, remediation of the damaged timber and the area around it covers containment, removal, repair and an anti-mould finish.
Sofas, mattresses and soft furnishings
Upholstered pieces hold moisture in their padding, so they're harder to rescue than wood. Light surface growth on covers and leather can often be cleaned, and our guide to saving leather, fabric and upholstery goes through each material. A mattress with mould on it is usually best replaced. Clothes and bags kept in mouldy furniture need sorting too, as set out in rescuing clothes from a damp wardrobe.
Stopping it happening again
Leave a gap of a few centimetres between furniture and outside walls, and avoid filling the corners of cold rooms with large pieces. Air rooms every day, including in winter, and keep wardrobes and drawers loosely packed. Dry laundry outside or in a ventilated room. Raise solid-based beds and sofas on legs or slats where you can. Before leaving a home closed for the season, open interior doors, wardrobes and drawers so air can move.
If furniture keeps going mouldy in the same room, the room has a moisture problem. The damp is diagnosed before the mould is treated, so the fix is aimed at the right problem. A damp check of the room and the wall behind your furniture gives you moisture readings in every affected room, a room-by-room moisture map sent to your phone, and a written report with the quote.
Furniture and walls both going mouldy? book an inspection from €75 and we'll sort the root cause, or call +357 99 759144.