Painting a Bathroom: The Right Paint, Proper Prep and Beating Condensation

Painting a bathroom is mostly a fight with water. The colour is the easy part. Whether the finish lasts for years or peels by spring comes down to steam, preparation and paint, in roughly that order.

Our interior painting work covers plenty of bathrooms, from windowless shower rooms to cold back-extension bathrooms in Victorian terraces. This is what actually works, and where the paint is the wrong thing to blame.

In short

• Sort the ventilation first, because no paint outlasts a bathroom that stays wet for an hour after every shower.
• Kill mould with a fungicidal wash before painting; never simply paint over it.
• Use a moisture-resistant bathroom paint, soft sheen or durable matt, not standard matt emulsion.
• Seal old water stains with a stain blocker such as Zinsser B-I-N or Cover Stain, or they will bleed through.
• Keep steam away from fresh paint for as long as the manufacturer advises, and keep the room warm while it dries.

Why bathroom paint fails: condensation

Every shower puts a surprising amount of water into the air. That warm, wet air settles on the coldest surfaces first: the ceiling, the outside wall and the window reveal. It condenses there, soaks into the paint and feeds mould. As a result, the same corner goes black every winter, however often it is wiped.

In Manchester, the classic problem bathroom sits in the back extension of a Victorian terrace. Think Withington, Levenshulme or Didsbury. It often has three cold external walls, a small window and a ceiling right under the roof. Flats and new builds bring a different problem: internal shower rooms with no window at all.

The warning signs are easy to spot:

• Black speckling in the ceiling corners and along the top edge of the tiles.
• Paint peeling in sheets above the bath or shower.
• Brown, sticky or glossy streaks running down newly painted walls.
• Bubbling on the window reveal, where condensation runs off the glass.

Those streaks are usually surfactant leaching rather than damp. They appear when water-based paint is steamed before it has cured. They wash off with warm water, although they can return once or twice before the film settles.

Sort the ventilation before painting a bathroom

This is the unglamorous part, and the most important. If the room stays wet long after a shower, new paint will fail exactly as the old paint did. Therefore, the extractor is checked before anything else.

A rough test is to hold a single sheet of toilet tissue against the grille with the fan running. If the fan cannot hold it there, it is probably moving very little air. Other things worth checking:

• Does the fan have an overrun timer, so it keeps running after the light goes off?
• Is the grille or duct clogged with fluff and dust?
• Is there a gap under the door, so replacement air can get in?
• Are the window trickle vents open, rather than painted shut?

Habits matter too. Keep the door shut while showering, so steam leaves through the fan, not onto the landing. Afterwards, leave the fan running and open the window for a while. A windowless shower room relies entirely on its fan, so that fan has to be a good one.

Preparation: killing bathroom mould first

Mould is not dirt. It is a living growth rooted into the paint and, often, the plaster beneath. Dry brushing or sanding it simply spreads the spores.

Instead, the affected area is treated with a fungicidal wash and left for the contact time on the label. It is then rinsed if the instructions say so, and left to dry.

Household bleach will lighten the staining. However, it is no substitute for a proper fungicidal treatment on porous plaster. Mould-resistant paint is not a cure either. Its fungicide protects the new film, but it will not kill a colony already living underneath.

With the mould dealt with, the rest of the preparation follows a steady routine:

• Walls and ceiling are washed with sugar soap to shift soap film, hairspray and grease, then rinsed with clean water.
• Flaking paint is scraped back to a sound edge, and the edges are feathered with abrasive paper.
• Cracks and holes are filled, sanded flush and spot-primed.
• Old water marks are sealed with a stain blocker before any emulsion goes on.
• Existing gloss on doors and skirting is degreased and keyed so the new coat grips.

That sequence is the backbone of our surface preparation and finishing service. It is also where most DIY bathroom jobs go wrong.

The best paint for bathrooms

Standard matt emulsion is the wrong choice for most bathrooms. Its open, porous surface soaks up moisture and marks as soon as it is wiped. You want a tighter, tougher film that sheds water and can be cleaned. The same goes for kitchens, where cooking steam does the shower’s job.

In practice, that means one of these:

• Kitchen-and-bathroom paint, often a soft sheen with a mould inhibitor in the film.
• Vinyl soft sheen, such as Dulux Trade Vinyl Soft Sheen or Johnstone’s Trade Covaplus Vinyl Soft Sheen.
• Durable matt, such as Dulux Trade Diamond Matt, for a flatter look in a room with good extraction.
• Mould-resistant coatings, such as Zinsser Perma-White, for rooms with a stubborn history.

For designer colours, Farrow & Ball’s Modern Emulsion and Little Greene’s Intelligent Matt are the tougher wall finishes in each range.

Sheen, however, is always a trade-off. More sheen sheds water better, but it also shows every dip in the plaster. Lumpy lath-and-plaster walls can look worse under a soft sheen, so a durable matt is often the better compromise there. Our guide to matt, eggshell, satin and gloss finishes goes into the differences.

Low-VOC paints and bathroom woodwork

If you want low-odour, low-VOC paint, read the label closely. Some clay and natural paints are breathable and lovely, but not intended for steamy rooms. Earthborn, for instance, points customers towards its wipeable Lifestyle Emulsion for kitchens and bathrooms. It is a common question with low-VOC and natural paint schemes in Prestwich.

For the door, skirting and bath panel, a water-based satin or eggshell is our usual choice. Oil-based whites yellow with age, and faster in rooms with little daylight. A windowless bathroom is the worst case of all.

Bathroom paint finishes compared

Ceilings, tiles and the shower area

The ceiling

The ceiling takes more condensation than any wall. When painting a bathroom ceiling, use the same moisture-resistant finish as the walls, not a standard matt ceiling white. Ceiling paints are designed to hide flaws, not to shed water.

Where a ceiling has peeled again and again, the old layers are usually the problem. They are taken back to a sound surface, sealed and repainted. On older houses, soft distemper is another culprit. Nothing sticks to it until it is washed off or sealed with a problem-surface sealer such as Zinsser Gardz.

Textured ceilings need extra thought, because every ridge holds condensation. Older textured coatings can contain asbestos, so they are never scraped or sanded before testing. Our guide to covering Artex ceilings explains the safe options.

Around tiles, the bath and the shower

Paint is not a waterproof finish. Anywhere the shower hits directly needs tiles or wall panels, not emulsion. We will paint neatly up to the tiling, but not inside the enclosure.

Cutting in along tiles is done by hand with a steady brush. Paint will not stick to silicone, so sealant is kept clean. If the silicone around the bath is black, it is worth having it renewed once the paint has cured. Decorator’s caulk is fine on dry joints, but it has no place in a splash zone.

Drying times: how long before showering after painting

Emulsion is usually touch dry in an hour or two, and ready to recoat within a few hours. Follow the manufacturer’s recoat time rather than guessing. However, touch dry is not the same as cured. A bathroom is the hardest test a young paint film can face.

Many manufacturers suggest keeping steam away for at least a day, and longer in cold weather. The guidance varies, so the tin has the final say. Keep the heating on and the fan running while it dries. Most water-based paints also list a minimum application temperature, often somewhere between 5°C and 10°C.

Losing the only bathroom is disruptive, so the programme is agreed up front. That includes the day the shower can be used again. Toilets and basins can usually still be used throughout. For commuters, it is often easiest to paint while the house is empty, like the weekday work we do in empty homes around Eccles.

For landlords, the same approach scales up. HMO bathrooms and end-of-tenancy turnarounds in Withington need tough finishes and a tight programme between tenants. That work sits within our residential and commercial painting service.

Where we draw the line

We will not paint over mould without killing it first. It is tempting, because a fresh coat hides it instantly. However, the mould keeps growing under the new film and is usually back within weeks. Then there are two layers to deal with instead of one.

We will also tell you if the extractor is the real problem. We are decorators, not electricians, so we do not fit or rewire fans. But there is little point paying for a new finish if the room still drips after every shower. In that case, the honest advice is to have an electrician upgrade the fan first, then book the decorating.

Sometimes the moisture is not condensation at all. A leaking shower tray, failed grout or a weeping pipe can soak a wall from behind. If a patch stays wet between showers, read our guide to painting a damp wall before you buy any paint.

Otherwise, painting a bathroom is a reasonable DIY job. A well-ventilated room with sound walls and no mould is a weekend’s work with the right paint. It is worth calling a professional when:

• Mould comes back within months of being treated.
• The ceiling keeps peeling, or it is textured.
• Old water stains bleed through every coat.
• A rental has to be turned around between tenants.

Get a free bathroom painting quote in Manchester

If your bathroom keeps going black in the corners, we will come and look at it. The ventilation, surfaces and any old stains are checked, then you get a clear written quote. The cost depends on the room’s condition and size, which is why we always look first.

Contact us for a free, no-obligation quote or call 07835 733353. We cover homes across Manchester and Greater Manchester, and every job is fully insured.

Frequently asked questions