The Best Anti-Mould Paints (2026): Zinsser Perma-White and Rivals Tested

By late October the same jobs come round again: black speckling across a bathroom ceiling, a grey bloom behind the wardrobe, a window reveal that never stays clean. Ordinary emulsion makes it worse - the binder and cellulose thickeners in a £12 tin of contract matt are, to a mould spore, food. Anti-mould paints lock a fungicide into the dried film so spores that land on it cannot establish, and the good ones keep working for five years or more.

We have used all four paints below on paying jobs: bathroom ceilings in Victorian terraces, north-facing bedrooms, rented kitchens with no extractor fan. They work, but only as the final step. Kill the existing mould, fix the moisture, then paint. Skip the first two steps and the best paint on this list will be speckled again by Christmas.

Anti-mould paint earns its money in rooms that are structurally sound but run damp in use: bathrooms and kitchens where steam condenses on cold ceilings, bedroom walls behind wardrobes, window reveals and north-facing corners. If what you have is condensation mould - soft black speckling that wipes off with a damp cloth - these paints will hold it back for years.

They are the wrong answer for structural damp. A saturated chimney breast, a failed damp-proof course or a leaking gutter pushes moisture through any paint film from behind, and no fungicide can protect plaster that is wet at its core. Diagnose first: our guide to getting rid of damp and mould explains how to tell condensation from penetrating and rising damp.

Tin-front claims are cheap, so we score on how each paint behaves over a full winter in a steamy room:

• •In-service mould resistance: does the film stay clean through to March on a ceiling that gets showered under twice a day?
• •Guarantee terms: how many years, and what the small print demands - almost all require a fungicidal wash first and two full coats.
• •Real coverage: makers claim 10-12m² per litre; over stain-blocked patches expect nearer 8m².
• •Scrubbability: an EN 13300 Class 1 film survives repeated hard washing without wearing through.
• •Cost per square metre at two coats, not headline tin price.
• •Colour and sheen choice, because a bedroom should not have to be brilliant white to stay mould-free.

Zinsser Perma-White is what we specify when a customer never wants to see mould again. The self-priming water-based film carries a genuine five-year mould-free guarantee, grips sound old paint without sanding, recoats in two hours and tints to hundreds of pale shades. At roughly £50 for 2.5 litres it is the dearest here, but two coats on a 4m² bathroom ceiling still costs under £20 in paint.

Ronseal's 6 Year Anti-Mould Paint is the budget pick we fit most often in rentals: white matt or silk only, but the guarantee is the longest here and a 750ml tin does a small ceiling twice. Dulux Easycare Bathroom is the choice when colour matters - a steam-resistant soft sheen in the full Dulux tint range, though its mould resistance is a film promise rather than a room guarantee, better suited to ventilated bathrooms than problem ones. If mould has never really been your issue, our wider guide to the best paint for bathrooms covers standard durable finishes.

The fourth pick solves a different problem. Thermilate InsOpaint is an anti-condensation paint: microscopic hollow spheres in the film insulate the wall surface just enough to keep it above dew point, so moisture never forms droplets in the first place. On a solid-brick external wall running 4-5°C colder than the room in January it makes a visible difference. Overcoat it with your chosen colour, and pair it with ventilation - it does nothing about the humidity itself.

Nine out of ten failed jobs we get called to were painted over live mould: the spores sit under the new film, the guarantee is void, and the speckling is back within weeks. The sequence below takes a weekend, but only an hour of it is painting:

• •1. Treat every visible patch with a fungicidal wash - a sodium hypochlorite or benzalkonium chloride product, applied and left for 15 minutes before wiping off. Dab dry mould rather than scrubbing spores across the room.
• •2. Wash the whole surface with sugar soap, rinse and leave 24 hours to dry - paint over damp plaster and adhesion fails.
• •3. Stain-block remaining shadows with a shellac-based primer, or old staining will ghost through both coats.
• •4. Apply two full coats, respecting the recoat window - two hours for Perma-White, four for Ronseal. One coat halves the biocide loading and voids the guarantee.
• •5. Fix the moisture. A bathroom extractor should shift at least 15 litres per second (Building Regulations Part F); run it 15 minutes past every shower. Keep the house between 40 and 60% relative humidity - our ideal indoor humidity guide covers measuring it, and a decent dehumidifier helps where ventilation cannot reach.

The same handful of errors accounts for nearly every disappointed review of these products:

• •Painting a wall that is damp from behind. Anti-mould paint is for condensation; on penetrating or rising damp it blisters and peels within months.
• •Skipping the fungicidal wash. Painting over live growth voids every guarantee mentioned on this page, without exception.
• •Applying one coat. The biocide dose assumes two; a single coat is a one-winter fix at best.
• •Expecting emulsion to survive direct water contact. A shower enclosure belongs to tiles or panels, and mouldy silicone or grout needs treating separately - paint cannot go over either.
• •Assuming anti-condensation paint dries the air. It only warms the surface; if the room shows signs of poor ventilation - streaming windows, musty fabrics - fix the airflow too.
• •Buying a generic 'kitchen and bathroom' paint with no stated guarantee. If the tin does not name a mould-free period, the film contains little or no biocide.

If you let property, a fresh coat over mould is not compliance - it is evidence you knew. Under the Homes (Fitness for Human Habitation) Act 2018 tenants in England can take a landlord to court over damp and mould, and councils can enforce through the Housing Health and Safety Rating System. Since 27 October 2025, Awaab's Law has required social landlords to investigate reported damp and mould within ten working days, share written findings, and start remedial work on significant hazards within five working days - with emergency hazards made safe inside 24 hours. The same standards are set to extend to private rentals under the Renters' Rights Act.

The defensible sequence is the same as for a homeowner, just documented: fix the moisture source - extractor fan, gutter repair, trickle vents - treat the mould, then repaint with a guaranteed product and keep the receipts. Perma-White on a prepared ceiling is a genuine five-year fix; straight over black mould it is a complaint waiting to happen.