How To Get Rid Of Mould On Walls Permanently

Quick answer: to get rid of mould on walls permanently, you have to deal with the moisture as well as the stain. Fix any leaks and improve ventilation first. Then, wearing a mask and gloves, scrub the mould off with a fungicidal wash or diluted bleach solution, let the wall dry completely, apply a sealer and repaint with an anti-mould paint. If you only paint over mould, it usually comes back within months in Singapore’s humidity. When we repaint an HDB flat, upgrading bedroom ceilings to anti-mould paint costs +$40 per bedroom (see our anti-mould painting service). Repainting it yourself? Follow our step-by-step guide to using anti-mould paint.

Why mould keeps coming back in Singapore homes

Mould needs moisture, and Singapore’s humidity supplies plenty of it. It usually comes back for one of these reasons:

• A leak that was never fixed: from a bathroom above, a pipe or a window seal.
• Condensation on bathroom ceilings and on walls cooled by air-conditioning. If a toilet ceiling is also peeling, see how to tell steam damage from a leak.
• Poor ventilation in bathrooms without an exhaust fan, store rooms and closed-up bedrooms.
• Furniture against outside walls: wardrobes pushed flat against a wall trap damp air behind them.
• Painting straight over mould, so the spores are still alive under the new paint.

How to remove mould from a painted wall, step by step

1. Protect yourself. Wear gloves, a mask and eye protection, and open the windows.
2. Stop the moisture. Fix the leak or condensation problem first, or the mould will return whatever you clean it with.
3. Apply a mould cleaner. Use a mould remover or a bleach solution diluted as the label says, and leave it on for the time stated. Never mix bleach with other cleaners: it can give off toxic gas.
4. Scrub and wipe. Scrub with a soft brush, wipe with clean water and repeat if stains remain.
5. Let the wall dry completely. This can take a few days in damp rooms. A fan or dehumidifier helps.
6. Seal any stains or patches. If dark marks remain, or you scraped off paint, apply a sealer so they don’t show through. See what sealer paint is for.
7. Repaint with an anti-mould paint, 2 coats, waiting for the recoat time on the tin.

Bleach, vinegar or mould remover?

When to call a professional

Get help if the mould covers a large area, comes back within weeks of cleaning, is on a ceiling under a bathroom, or comes with peeling or bubbling paint (see why paint peels). These usually point to a leak or damp that needs fixing before any repainting.

Stopping mould from coming back

• Run the bathroom exhaust fan or open the window after showers.
• Wipe condensation off ceilings, mirrors and window frames.
• Leave a small gap behind wardrobes on outside walls.
• Use an anti-mould paint in bathrooms, kitchens and on bedroom ceilings. See which paint to use in humid rooms.

What it costs if we repaint it

In our HDB packages, upgrading bedroom ceilings to anti-mould paint costs +$40 per bedroom, a sealer adds +$40 per room, and major peeling and putty repair is $40 to $290 depending on the damage. See our anti-mould painting service and full price list, or WhatsApp us photos of the mould for a quote.

Frequently asked questions

Does painting over mould get rid of it?

No. The mould keeps growing under the new paint and usually shows through within months. Clean it, fix the damp and let the wall dry before painting.

Is black mould on a ceiling dangerous?

Mould can trigger allergies and breathing problems in some people, especially children and people with asthma, so it is worth removing promptly and fixing the cause. If anyone at home is affected, ask a doctor for advice.

Can I use bleach on a painted wall?

Yes, if it is diluted as the label says and the room is ventilated. Test a small hidden spot first, because bleach can fade coloured paint.