Painting Cornices and Coving in London Properties: Technique and Common Mistakes

Cornices and Coving: The Distinction That Matters

In London's period housing stock, you will encounter both genuine cornices and coving, and the distinction matters for how you paint them.

Cornice refers to the decorative plaster moulding that runs at the junction of wall and ceiling in Georgian, Victorian, and Edwardian properties. Original cornices are run or cast in lime plaster and can be extraordinarily detailed — egg-and-dart mouldings, acanthus leaves, guilloche patterns, dentil courses. The profile is part of the room's architectural language and should be treated with care.

Coving typically refers to a simpler curved or moulded section — often plaster or expanded polystyrene — used to conceal the wall-ceiling junction. It is less architecturally specific than a profiled cornice but still requires competent painting.

Both require patience and the right technique. Rushing cornice painting produces a result that looks amateurish and draws the eye for all the wrong reasons.

Preparation

Before painting, assess the condition of the cornice itself. Common problems on London period properties include:

• Cracks at the junction with the ceiling or wall — these are usually movement cracks and must be filled before painting. Use a flexible filler on hairline cracks; if the crack is wider than 2mm, investigate whether there is ongoing movement before filling.
• Paint build-up in profile details — decades of successive coats can obscure fine moulding detail. If the profile reads as soft or blurred, it may be worth stripping back with chemical stripper and a stiff brush before repainting.
• Loose sections — tap along the cornice and listen for a hollow sound. Sections that have separated from the ceiling must be re-fixed (using screws and plasterboard fixings or lime plaster repair) before painting. Do not paint loose cornice sections; the movement will crack any new paint film quickly.

Fill all cracks and imperfections, allow the filler to cure fully, and sand smooth before priming. On bare plaster repairs, a coat of diluted PVA or a proprietary plaster primer seals the surface and prevents patchy absorption.

Product Choice

Cornices are nearly always painted in a water-based finish — eggshell or satin on the moulding if it is to differ from the ceiling, or a quality emulsion if painted in the same finish as the ceiling. Oil-based paints are occasionally used on cornices in high-specification projects; the harder film they produce resists dings and scuffs well in hallways and reception rooms that receive heavy use.

Avoid cheap trade emulsions on detailed cornices. A high-quality, high-opacity emulsion gives better coverage in a single coat and produces a crisper finish in the profile details.

Cutting In: The Technique

The most common mistake on cornices is applying too much paint at once. A heavily loaded brush on a complex profile will pool in the recesses and take a long time to level out — if it levels at all. The correct approach is:

• Load the brush, then tip off excess on the edge of the tin or a board.
• Work the paint into the profile with light, probing strokes, ensuring coverage in the deepest recesses first.
• Follow with longer strokes along the length of the cornice to level and unify the film.
• Maintain a wet edge throughout each section — do not allow sections to partially dry before rejoining them.

When cutting in at the ceiling line above the cornice, use a 25mm or 38mm cutting-in brush rather than a masking tape approach. Masking tape applied to textured or painted ceilings rarely produces a clean line — it tends to bleed or pull paint when removed. A steady hand and a well-loaded brush give better results.

For the wall-side cut in below the cornice, the same principle applies. Work a clean, consistent line along the bottom edge of the moulding, using the brush tip and working with short, controlled strokes.

Two-Tone Approaches

In period rooms with well-defined cornices, painting the cornice in a different colour to the ceiling and walls is historically appropriate and can be very effective. The most common schemes are:

Cornice in the ceiling colour — clean and recessive; makes the room feel taller by visually extending the ceiling plane.

Cornice in the wall colour — grounds the moulding in the room rather than the ceiling, and works particularly well in rooms with strong, saturated wall colours.

Cornice in a third colour — a cream or off-white cornice between a coloured ceiling and coloured walls was a common Georgian and Victorian convention. It reads as considered and traditionally correct.

Picking out details — on elaborate cornices, individual elements (dentils, egg-and-dart ovolo, leaf-and-dart cove) can be picked out in contrasting colours. This requires a fine artist's brush and considerable patience, but the effect in a formal reception room is striking.

When executing a two-tone scheme, the sequence is: ceiling first, then cornice, then walls, cutting in against the previous colour at each stage.

Common Mistakes to Avoid

• Painting a damp or freshly repaired cornice before the substrate has fully dried
• Using the same paint as the ceiling without checking that the sheen level is appropriate for the profile
• Applying a single heavy coat rather than two thinner coats
• Failing to caulk the junction between cornice and ceiling or cornice and wall before painting, leaving a visible crack that reappears within months

Cornices and coving are a significant visual feature in London period rooms. Getting the painting right is worth the investment in time and preparation. For period rooms where the cornices are a genuine architectural feature, contact us here to discuss the right approach. Request a free quote and we can assess the condition and specification in person.