Painting a Bathroom in a London Property: Products, Preparation, and Finish
A practical guide to painting bathrooms in London homes — moisture-resistant paint systems, surface preparation, ventilation requirements, tile paint, and the finishes that last in a wet environment.
Why Bathrooms Fail Faster Than Any Other Room
Bathrooms are the most demanding environment for paint in any residential property. High humidity, frequent temperature changes, steam, direct water splash, and soap residue combine to create conditions that expose every weakness in a paint system within months. In London properties — many of which have older ventilation and smaller window areas than modern building regulations would require — these conditions are intensified.
A bathroom painted with the wrong product, or correctly specified but poorly prepared, will begin to show mould, peeling, or chalking within six to twelve months. Getting the specification and preparation right from the start is the only way to achieve a finish that holds for five or more years.
Product Selection: What Actually Works
The core requirement for a bathroom paint is moisture resistance — specifically, the ability to resist the absorption of water vapour into the paint film without permitting the build-up of condensate behind the film. These two properties are often described as if they were one, but they are distinct.
Specialist bathroom emulsions from major manufacturers — Dulux Bathroom+, Crown Bathroom, Johnstone's Bathroom — contain a higher proportion of vinyl or acrylic resin than standard emulsion and are formulated to resist mould and surface water. They are suitable for walls and ceilings in standard domestic bathrooms. They are not suitable for areas of direct water contact (behind the basin, inside the shower enclosure, or directly above a freestanding bath) — these areas need a fully waterproof finish or wall tiles.
Eggshell and satinwood on bathroom walls have become popular for their more washable, semi-reflective surface. A water-based eggshell or satinwood gives a finish that wipes clean easily and is more resistant to accidental water splash than a matt emulsion. It is also more forgiving of condensation — water beads on the surface rather than being absorbed. The trade-off is that eggshell emphasises surface imperfections more than matt, so preparation needs to be thorough.
Oil-based satinwood is the traditional choice for bathroom woodwork — skirting, door frames, window frames, and any timber panelling. It gives a harder, more moisture-resistant finish than water-based alternatives and is still the correct specification for bathroom environments with very high humidity. Allow full curing time between coats (24 hours minimum in cool conditions, 12 hours in warm) and ventilate the room during application and curing.
Anti-mould additives are available as liquid additions to standard emulsions. These can be effective in a bathroom where the primary problem is surface mould rather than peeling or adhesion failure — but they are not a substitute for a properly moisture-resistant product and correct ventilation.
Preparation: The Critical Stage
Bathroom preparation is more demanding than other rooms because the surface is almost certainly contaminated with soap, grease, silicone overspray, or mould before you begin.
Wash down all surfaces with a sugar soap solution and rinse thoroughly. In a bathroom that has visible mould, treat the affected areas with a bleach-based mould killer, leave for the manufacturer's dwell time, and rinse clean. Allow to dry completely — in an enclosed bathroom this may take longer than expected. Use a dehumidifier or keep the window open to accelerate drying.
Sand back any areas of peeling paint to a firm edge. Feather the edges with fine sandpaper rather than leaving a hard step. Any areas of bare plaster or plasterboard should be primed with an appropriate primer before topcoats — plasterboard in particular is very absorbent and will draw the moisture from the first topcoat unevenly, causing sheen variation in the finish.
Silicone contamination is one of the most common causes of bathroom paint failure. If silicone sealant has been applied near the surfaces to be painted, or if a silicone-based product has been sprayed in the room, the silicone may have transferred to the wall surface. Silicone is invisible and prevents paint adhesion — standard preparation will not remove it. If you suspect silicone contamination, clean the surface with a dedicated silicone remover before priming.
Tile Paint: Realistic Expectations
Tile painting is a common request in London bathroom renovations — replacing tiles is disruptive and expensive, and paint over tile can be a cost-effective solution in the short to medium term. The important word here is realistic.
Specialist tile paints (Ronseal Tile Paint, Rustins Tile Paint, and others) bond to glazed ceramic tile surfaces through a combination of adhesion promoter and hard film-forming resin. When correctly applied to a properly prepared surface, they can last three to five years in a family bathroom before showing signs of wear at high-contact points.
Preparation for tile paint is non-negotiable: degrease with acetone or a dedicated cleaner, abrade the glazed surface lightly with fine wet-and-dry paper to create a mechanical key, wipe clean, allow to dry, and apply the tile paint in thin coats. Do not apply tile paint in thick coats — it does not self-level on a non-absorbent surface and will show brush marks or sag. Two to three thin coats, fully cured, outperform one thick coat every time.
Tile paint is not appropriate for shower enclosures where water contact is constant. Use it on feature tiles, splashbacks, or floor-level tiles where direct water contact is intermittent.
Ventilation: The Factor Painting Cannot Fix
No paint system will compensate for inadequate ventilation in a bathroom. Condensation that cannot escape will find a path behind the paint film, causing blistering and mould whatever product is used. In London properties with window-only ventilation, this is a significant limitation.
Before specifying a bathroom repaint, assess the ventilation. If the existing extractor fan is undersized, poorly positioned, or absent, advise the client to address this before decoration. A correctly sized extract fan — positioned high in the room, ideally within 600mm of the shower — removes the moisture at source. The difference in paint longevity between an adequately ventilated and a poorly ventilated bathroom of the same dimensions is measured in years, not months.
For a bathroom decorating project in London, contact us here or request a free quote.