Painting Internal Doors in London: Technique for Flush and Panelled Doors

The Internal Door: A Test of Painterly Skill

There are few surfaces that reveal the quality of a decorator's work quite as clearly as a well-painted internal door. At close quarters, with light raking across the surface, every brush mark, drip, missed section and uneven sheen is visible. Get it right and it is a quietly impressive thing. Get it wrong and it dominates the room in the worst possible way.

London properties present a wide range of internal door types. Victorian and Edwardian terraces in areas such as Battersea, Fulham and Islington typically have original four or six-panel doors in pine or deal, full of character. Interwar properties often have simpler two-panel doors. Modern flats and newer conversions frequently have flush doors — flat-faced, featureless and in some ways harder to finish well than their panelled counterparts.

This guide covers both, along with the question of finish level that comes up in almost every conversation.

Preparing the Door Before Painting

Good preparation is non-negotiable. For a previously painted door that is being refreshed:

• Remove door furniture — handle, escutcheon, hinges if possible — rather than masking around them. Paint that builds up around ironmongery looks immediately unprofessional.
• Wash the door down with sugar soap to remove grease, fingerprints and grime accumulated around handles.
• Fill any holes, dents or cracks with a fine surface filler and sand smooth when dry.
• Lightly sand the entire door with 120-grit paper to provide a key for the new paint. If the existing surface is oil-based and you are switching to water-based, a good scuff is particularly important.
• Wipe down with a clean damp cloth to remove all dust and allow to dry.

If the door has been stripped to bare timber, prime with a suitable wood primer and allow to dry fully before topcoating. Bare end grain at the top and bottom of the door should receive an extra coat of primer as it is highly absorbent.

Painting Panelled Doors: The Correct Order of Work

This matters more than many people realise. Paint a panelled door in the wrong sequence and you will end up with lap marks and wet edges where paint from later sections overlaps partially dried areas from earlier ones.

The correct order is:

1. Mouldings — the angled edges around each panel
2. Panels themselves — working from top to bottom, fill each panel and finish with strokes in the direction of the wood grain
3. Muntins — the vertical dividers between panels
4. Rails — the horizontal cross-members, working top to bottom
5. Stiles — the full-height vertical sections on each side of the door
6. Door edge — the leading edge and, if accessible, the hinge edge

Working in this sequence means each section is still wet enough to blend into the next when you reach the junctions, avoiding the tide marks that result from painting sections independently and letting them dry before meeting.

In Kensington and Mayfair townhouses where original six-panel doors with deep mouldings are common, take time with the moulding sections. Use a smaller brush (a 25 mm or 38 mm cutting brush) to work the paint into the recesses, then follow up immediately with a slightly larger brush to lay off along the moulding run.

Painting Flush Doors: Avoiding Lap Marks

Flush doors look simple but are deceptively difficult to paint evenly. The large, flat surface shows any variation in paint application clearly, including lap marks where a section of wet paint is overworked as it begins to dry.

The key is to work quickly and in a consistent pattern, dividing the door mentally into a grid of sections — typically six to eight sections depending on door width — and working each section into the next while the paint is still wet. Use a wide brush (75 mm or larger) or a small short-pile roller for flush doors. A roller gives a more even finish across the flat surface; a brush is used to cut in edges and any awkward areas.

Apply the paint in vertical strokes, then lay off (final light strokes to remove brush marks) in the direction of the grain — which on a flush door is usually vertical. Keep a wet edge and move efficiently. Do not go back over sections that have begun to skin over.

Gloss, Satinwood or Eggshell?

The choice of sheen level for internal doors is partly practical and partly a matter of style. Traditional gloss has largely fallen from favour in contemporary London interiors — it shows every imperfection and can look stark in modern spaces. However, it remains appropriate in period properties where a high-sheen finish complements original features, and it is the most durable option.

Satinwood (typically 30–50% sheen) is the current workhorse of interior woodwork in London. It is durable, easy to clean and flatters the door without dominating it. Eggshell (roughly 10–20% sheen) is increasingly popular in contemporary spaces where a flatter, more unified look is wanted — doors, walls and woodwork all at a similar sheen level creates a calm, cohesive interior popular in Chelsea and Notting Hill.

Whatever the choice, apply at least two topcoats, allowing full drying time between coats, and sand lightly with 240-grit paper between coats for a smooth, professional result.

Handling and Rehinging

Once painted, leave the door off its hinges for as long as possible — ideally overnight — to allow the paint to harden before it is subject to opening and closing. Paint on door edges that are still soft will be damaged the first time the door is opened. When rehanging, take care not to let the door slam and chip the fresh paint on the closing edge.

Refit all door furniture last, once the paint is fully cured. This is one of those finishing details that separates a trade-quality result from a rushed DIY job.