How to get rid of mould, room by room

Mould is a living organism, not a stain. It grows from spores that are already floating in the air of every home, everywhere in the world. Those spores sit harmless as dust until they land somewhere with three things at once: moisture, a food source such as dust, timber, plaster, paint or fabric, and still air. Give them all three and a colony establishes within a day or two. Take away any one of them and it cannot.

This is why mould is so predictable about location. It shows up in the corner of the bathroom ceiling, the back of the wardrobe, the bottom of the window, the wall behind the bed. These are the coldest, dampest, least ventilated spots in the house, and they are the same in most Australian homes. Once you understand how mould finds moisture, food and still air to grow, you can read a room and predict exactly where it will appear next.

The single most common mistake is treating the stain and ignoring the moisture. Wipe the patch, walk away, and the spores that survive in the surface simply regrow the moment the damp returns. Every room below is really a moisture problem wearing a mould disguise, so the fix is always two jobs: clean what is there now, and change the conditions that grew it.

Before the room-by-room detail, here is the method that sits underneath all of it. It is the same four moves whether you are cleaning a ceiling or a mattress.

1. Protect yourself and the room. Open a window, wear gloves, and keep pets and children out of the space while you work. Never dry-brush or dry-sand mould, because that flicks spores across the room to start new colonies elsewhere.
2. Remove the growth from the surface. Wipe with a damp cloth so the mould comes away onto the cloth rather than into the air. Non-porous surfaces such as tiles, glass and sealed paint clean up fully. Porous ones such as raw timber, plasterboard and grout hold roots deeper and need more work or replacement.
3. Dry the area thoroughly. Mould cannot regrow on a genuinely dry surface, so this step matters as much as the cleaning.
4. Fix the moisture, then keep the air working for you. A cleaned surface stays clear only while the room is dry and the air keeps moving, because fresh spores are always drifting in from outside. This is where a natural mould-defence oil earns its place: run it in a diffuser so the oils spread through the room and meet returning spores in the air, and you can also put a few drops in water and lightly mist the cleaned surface itself, where the oils work on direct contact.

Nothing removes mould for keeps, because the spores are always in the air and drift back to any damp surface. The honest goal is control: clean well, dry hard, fix the water, and keep a light routine going so it rarely gets a foothold again. For the standing habits that hold across the whole house, the full prevention guide for Australian homes goes deeper than we can here.

The bathroom is where nearly every Australian home meets mould first, and understandably so. A hot shower fills the small room with warm, wet air. That moisture condenses on the coolest surfaces it can find: the ceiling, the grout lines, the silicone around the bath, the window. If the extraction fan is weak, missing or switched off too soon, the damp lingers for hours and the black speckling starts in the corners above the shower.

Treat it in the order above: ventilate, wipe the growth away with a damp cloth, dry the surface, then keep the fan running for a good twenty minutes after every shower and leave the door open so the room clears. A squeegee on the tiles and screen after showering removes the standing water mould needs. The ceiling is the trickiest spot because it is the coldest and hardest to reach, so our deep guide to black mould on a bathroom ceiling covers the reach, the safe wiping method and how to stop it returning.

The grout and silicone are a special case. Water sits in the tiny pores of grout and along the edge of old silicone, and once mould roots into either, surface cleaning only lifts the top layer. Badly stained silicone is usually cheaper and cleaner to cut out and reseal than to rescue. For the full method on both, see our guide to mould in shower silicone and grout, which walks through when to clean and when to replace.

Bedrooms look dry, which is why their mould surprises people. The moisture comes from us: two adults asleep release a good deal of water vapour into the air over eight hours. In a closed room with the door and windows shut all night, that vapour has nowhere to go, so it condenses on the coldest surfaces, the external walls, the window, and any wall hidden behind a large headboard or wardrobe where the air is dead still.

The fixes are gentle and cheap. Crack a window overnight or first thing in the morning to let the moist air out. Pull beds and heavy furniture a few centimetres off cold external walls so air can move behind them. Make the bed later rather than the moment you rise, so the sheets and mattress air off instead of trapping the night's moisture. If a patch has already grown on the wall or behind furniture, clean it with the damp-cloth method and keep that corner ventilated from then on.

A wardrobe is a small, sealed, unventilated box, often built against a cold external wall, and that is close to ideal conditions for mould. Pack it tight with clothes and the air stops moving entirely. Put anything away even slightly damp, a coat still wet from rain or a towel that never fully dried, and you have added the water too. The result is the musty smell and the pale speckling on shoes, leather and the backs of garments.

Fix the air first: thin out an overpacked wardrobe, leave the door ajar when you can, and never store damp items. Wipe the interior and any affected surfaces, and dry clothes fully before they go away. Washable fabrics can often be laundered clean, while delicate and structured pieces may need specialist cleaning. Our detailed guide to mould in a wardrobe and on clothes covers rescuing different fabrics and keeping the whole space dry.

Wall mould is a signal worth reading carefully, because it separates into two very different problems. Surface mould, the speckling on a cold external wall or in a still corner, is condensation feeding growth on the paint, and it cleans up with the standard method. Mould that keeps returning in the same patch, or that bleeds through fresh paint, usually means water is reaching the wall from behind: a roof or gutter leak, rising damp, or a plumbing fault inside the cavity.

For the surface kind, wipe it back, dry it, and improve the airflow in that part of the room so the returning spores struggle to resettle. For the returning kind, no amount of wiping will hold until the water source is found and fixed, and painting over it only hides the problem for a few weeks. Our full walkthrough on getting rid of mould on walls explains how to tell surface growth from a hidden leak, and how to treat plasterboard and painted surfaces without spreading it.

Windows are the clearest lesson in how mould works, because you can watch the moisture form. Warm indoor air meets the cold glass overnight and condenses into the water you see beading on the pane each morning. That water runs down and pools in the frame and along the sill, where dust gives it something to feed on, and by winter the seals and corners are black.

The daily fix is simple: wipe the condensation off the glass and sill each morning before it soaks in, and let the room air out so the overnight moisture escapes rather than settling. Clean existing growth from the frame and sill with the damp-cloth method, paying attention to the rubber seals where roots hold. Our guide to mould on window sills and frames goes further on the seals, the frame tracks and the timber sills that suffer most.

Kitchens generate a lot of moisture and hide it well. Boiling pots and a steaming kettle pour water vapour into the air, and a rangehood that vents nowhere useful just recirculates it. The damp then settles where you cannot see it: behind and under the sink where a slow leak feeds the cupboard, along the fridge door seals, behind the kickboards, and in the dead corner of a pantry.

Run the rangehood whenever you cook and put lids on pots to cut the steam at the source. Check under the sink regularly, because a slow leak there is one of the most common hidden mould sources in the house. Wipe the fridge seals and any damp cupboard corners, dry them, and keep an eye on the spots you rarely open. As with every room, the cleaning is the easy half and the moisture is the real fix.

The laundry packs more water sources into a small space than anywhere else in the home. Front-loader washing machines are notorious for it: the rubber door seal traps water in its folds and grows a black rim, and the detergent drawer stays wet between washes. A dryer that vents into the room instead of outside dumps litres of moisture into the air, and wet washing hung up to dry indoors does the same more slowly.

Leave the washing-machine door and detergent drawer open between loads so they dry out, and wipe the door seal regularly, pulling back the folds where the water hides. Vent the dryer outside if you possibly can, and dry washing outdoors or in a well-aired space rather than a closed laundry. Wipe down the splash areas around the tub and keep the room ventilated, because a warm damp laundry is a mould nursery whenever the air stops moving.

Carpet is one of the harder surfaces, because it is thick, porous and slow to dry, and the mould often grows in the backing and underlay where you cannot see or reach it. It takes hold after a spill that was never dried out, a flood or leak, or on carpet laid over a cold concrete slab that sweats with condensation and rising damp from below.

Small, fresh surface patches on a synthetic carpet can sometimes be cleaned and dried thoroughly, ideally with the help of fans and dry air. But once mould is established in the backing or underlay, or the carpet has been soaked in a flood, cleaning the pile rarely reaches the growth underneath, and replacing the affected section is often the honest answer. Our guide to mould in carpet covers assessing how deep it goes and dealing with the slab beneath.

A mattress grows mould from underneath, which is why it is so often missed until you flip it. The moisture a sleeping body releases overnight has to pass through the mattress, and if the underside sits against a solid base or directly on the floor with no airflow, that moisture has nowhere to escape and pools against a cold surface. The result is the dark blotching on the base of the mattress and the slats or floor below.

Prevention is mostly about airflow: use a slatted bed base so air can circulate underneath, lift a floor mattress off the ground, and stand the mattress up to air in the sun now and then. A soaked or deeply grown mattress is difficult to recover, because the growth reaches into the foam and padding you cannot clean. Our guide to mould on a mattress covers assessing surface versus deep growth and setting the bed up so it stays dry.

Curtains and blinds get mouldy for a borrowed reason: they hang against the coldest, dampest surface in the room, the window. All that overnight condensation transfers into the fabric or settles on the slats, and because curtains are rarely washed and blinds rarely wiped, the growth has weeks to establish before anyone notices the speckling along the bottom edge.

Most washable curtains can be laundered clean, following the care label, and dried fully before rehanging. Blinds wipe down surface by surface, with attention to the cords and the top of each slat where dust and damp collect. The lasting fix is the window behind them: deal with the condensation there and the fabric stops getting fed. Our guide to mould on curtains and blinds covers the different fabrics and blind types and how to keep them dry.

Every room on this page comes back to the same three levers, and once you see them you can run the whole house on a light routine. Cut the moisture at the source: lids on pots, fans during and after showers, dryers vented outside, no damp clothes put away. Move the air: open windows daily, leave gaps behind furniture and inside wardrobes, and never let a room sit sealed and still for days. Fix the water faults: a leaking gutter, a weeping pipe or rising damp will beat any amount of cleaning until it is repaired.

On top of those habits, keeping the air moving in the rooms that always seem to grow mould, the bathroom, the wardrobe, the window reveals, stops the returning spores from getting comfortable between cleans. That is where a natural mould-defence oil fits into the routine, running quietly in the background as maintenance rather than a one-off rescue.

First Light is our six-oil essential-oil blend for mould defence, made in Australia. It is not a cleaner: you clean the mould with the normal method for that surface first, then use First Light so it does not settle back. The main way is a diffuser, but you can also put a few drops on a dish in a cupboard, or a few drops in water and lightly mist surfaces you have already cleaned. It works both in the air and on the surfaces it touches. Lab tested: 99.2% reduction in black mould on direct contact. If you want to set up that light maintenance routine across your home, our range pairs First Light with the waterless diffuser that runs it.