Painting Bathrooms in London Properties: Moisture, Products, Mould Prevention and Tile Paint

The Bathroom Painting Challenge in London Properties

London bathrooms present a specific decorating challenge: high humidity, limited ventilation, and — in period properties — older plasterwork that is often already compromised by years of steam exposure. Paint that performs elsewhere in the house fails in a poorly ventilated bathroom within months. Getting it right requires the correct product choice and, critically, understanding and addressing the root causes of moisture before a brush goes anywhere near the wall.

Ventilation First: Why Paint Alone Is Not the Answer

The most important thing we tell clients before painting a bathroom is this: no paint system, however well specified, will prevent mould and condensation damage in a bathroom with inadequate ventilation. Paint can resist moisture and resist mould spores for a time, but chronic condensation will eventually defeat any coating.

London period bathrooms frequently have:

• No mechanical extract ventilation — original bathrooms were either ventilated by an operable window or simply not ventilated at all. If there is no extractor fan and the window is rarely opened, condensation will be a persistent problem.
• Undersized extractor fans — many installations use a fan rated at 60 to 70 m³/hour where a shower room requires a minimum of 90 to 120 m³/hour. We recommend Vent-Axia Sentinel or Manrose fans with humidity sensors as a practical upgrade.
• Cold external walls — solid-wall Victorian bathrooms with an external wall on one or two sides create a cold surface against which warm bathroom air condenses readily. This is a thermal problem, not primarily a paint problem.

Where ventilation is genuinely adequate, the right paint system will protect the walls and ceiling effectively. Where it is not, we say so at the survey stage.

Specialist Bathroom Paint Versus Standard Products

Dedicated bathroom paints are formulated with:

• Biocide additives that inhibit mould growth within the paint film
• Reduced water vapour permeability to resist steam penetration
• Slightly harder film than standard emulsion to withstand condensation and wiping

The products we specify most frequently:

Dulux Bathroom Plus — a widely available mid-market option with good biocide loading and a steam-resistant formulation. Available in matt and soft sheen. Adequate for a well-ventilated bathroom. Mid sheen is preferable as it is more washable than matt.

Zinsser Perma-White — our preferred product for bathrooms with known damp or condensation problems. It is a self-priming, mould-resistant paint with a harder film than standard emulsions. The manufacturer guarantees against mould growth on the paint film for five years. Available in satin and semi-gloss. We use this on any bathroom where we have found existing mould or where ventilation is borderline.

Little Greene Intelligent Matt and Eggshell — for clients prioritising colour quality and appearance, Little Greene's water-based eggshell is more moisture-resistant than their standard matt and sits beautifully in a period bathroom. It does not have the specific mould-inhibiting properties of Zinsser Perma-White, so it is reserved for well-ventilated bathrooms where colour accuracy matters more than maximum moisture resistance.

Standard emulsion — not recommended for bathrooms under any circumstances. The film is too soft, too moisture-permeable, and lacks biocide protection.

Preparation of Bathroom Surfaces

Bathroom preparation is more demanding than other rooms:

Removing existing mould — any existing mould must be treated before redecoration. We apply Zinsser Mould Killer (diluted to manufacturer specification), leave for 24 hours, scrub off and rinse. Mould staining in plaster is then sealed with Zinsser BIN shellac-based primer before any emulsion is applied. BIN is the only primer we trust to reliably block mould staining bleed-through.

Blown plaster — steam penetration over years frequently causes plaster to blow on external walls and around shower and bath enclosures. We identify all blown areas with a tapping test, cut out and re-plaster. Painting over blown plaster simply moves the problem to a later date.

Sealant junctions — the junction between paint and bath, shower tray, basin or tile is sealed with a mould-resistant silicone after painting. We use Everbuild Everflex 500 in white or clear, applied as a single bead and tooled smooth.

Mould Prevention: A Systematic Approach

Beyond paint specification, mould prevention in a London bathroom requires:

1. Treat and remove all existing mould before painting
2. Seal with Zinsser BIN over any affected areas
3. Apply Zinsser Perma-White or equivalent mould-resistant paint
4. Ensure sealant junctions are intact at all wet-to-dry transitions
5. Address ventilation — this is the only long-term solution

We do not recommend anti-mould paint additives mixed into standard emulsion. These products contain a biocide dose that is significantly lower than a purpose-formulated mould-resistant paint and the consistency of mixing cannot be guaranteed.

Tile Paint: Is It Worth It?

Tile paint — typically Ronseal Tile Paint or Rust-Oleum Tile Transformations — is a specialist coating designed to adhere to glazed ceramic tiles. It can be a cost-effective alternative to retiling where the existing tiles are sound and well-adhered but the colour is wrong.

Our honest assessment: tile paint works adequately on wall tiles in a bathroom that is used for bathing rather than showering. On tiles that receive direct shower spray, tile paint is exposed to mechanical water impact and flexing of the tile-adhesive bond. Most tile paint applications in shower enclosures start delaminating within two to three years.

If tiles are on bath surrounds or walls receiving only splash (not direct shower flow), a properly prepared and applied tile paint — scuff-sanded at 240 grit, wiped with isopropyl alcohol, primed with Zinsser Bulls Eye 1-2-3, then two coats of Ronseal Tile Paint applied by small foam roller — will last four to five years. Manage client expectations accordingly.

Colour Choices for London Bathrooms

Bathrooms in period London properties suit colours that are calm without being blank:

• Blue-greens and teals — Farrow & Ball's Blue Ground or De Nimes, Little Greene's Aquamarine Deep. These read beautifully with white sanitary ware and chrome or brass fittings.
• Warm off-whites — in a small bathroom without much natural light, a warm white such as Farrow & Ball Pointing or Little Greene Linen keeps things light without the harshness of pure white.
• Deep greens and charcoals — in a larger or well-lit bathroom, a dark all-over colour such as Farrow & Ball's Studio Green or Little Greene Obsidian Green creates a dramatic and surprisingly calming space.

Avoid high-gloss finishes on walls — they show condensation runs and every surface imperfection.

Arranging a Bathroom Repaint

If your bathroom is overdue for redecoration, we provide a full service including surface preparation, mould treatment, correct product specification and a professional finish. Request a free quote or contact us to discuss your bathroom.