Painting a Period Front Door in London: Preparation, Stripping, Sealants and Finish Choice

Why Period Front Doors Fail Faster Than They Should

A period front door is one of the most exposed surfaces a decorator will encounter. It faces every weather extreme — UV from the south and west, driving rain, frost — while being opened and closed several times a day and touched constantly. Despite this, many London period front doors receive exactly the same preparation and products as interior woodwork, which is why they peel, crack and blister within two or three years of being painted.

A correctly painted period front door should last five to seven years before requiring full preparation and recoating. Here is how to achieve that.

Assessing the Existing Paint Condition

Before any tools are picked up, the door is assessed. The question is not whether it looks bad — it probably does, or you would not be reading this — but how many layers of paint are present and what condition the timber beneath them is in.

We carry out a simple assessment:

• Probe test on moulding bottoms — the bottom of door mouldings and the lower rail are where moisture collects and rot begins. We probe these areas with a sharp point. Any softness indicates rot that must be treated before painting.
• Adhesion test — a piece of masking tape pressed firmly onto the paint surface and pulled sharply indicates whether existing paint is well-bonded or loose. If significant paint lifts, stripping back further is indicated.
• Layer count — we nick the paint edge at a joint to estimate layer depth. More than six to eight layers (approximately 2mm of paint film) will crack no matter what goes on top and should be stripped.

Stripping Back to Bare Timber

Where the existing paint is compromised or too thick to overcoat successfully, we strip back to bare timber. This is not a quick task and should not be rushed.

Heat gun method — a variable-temperature heat gun (Steinel HG 2620 E or similar) set to 200–250°C. We keep the gun moving and do not hold it stationary — the goal is to soften paint for scraper removal, not to scorch the timber. Flat panels are done first with a wide-blade scraper; moulded sections require a shaped scraper or moulding scraper to get into profiles without gouging.

Chemical stripper — for detailed mouldings and around glazed sections where heat gun use risks cracking the glass, we use Peelaway 7 paste, applied thickly and covered with the supplied paper blanket for six to eight hours. This lifts paint in a single peelable layer. Neutralise thoroughly with clean water and allow the timber to dry for a minimum of 48 hours before priming.

Do not dry-sand — sanding of old paint risks lead dust. We wet-sand any residual paint using wet-and-dry paper at 180 grit with a drop of washing-up liquid in water, keeping the surface damp throughout.

After stripping, bare timber is inspected for rot in earnest. Any soft wood is cut back to firm timber. Voids over 15mm deep are packed with a two-part epoxy wood filler (Ronseal High Performance Wood Filler or Repair Care Dry Flex). Smaller voids are filled with a good exterior-grade filler such as Toupret Wood Repair or Ronseal Interior and Exterior Wood Filler (not a standard interior filler, which will crack when the timber moves).

Flexible Sealant at Frame Junctions

The most common cause of front door paint failure is moisture entering at the junction between the door frame and the surrounding masonry or rendered wall. This junction moves — thermally, with moisture changes, and with any building movement — and a rigid filler or paint cannot accommodate that movement.

After stripping and priming but before any top coats, we apply a flexible sealant bead at every frame-to-masonry junction:

• Product: Everbuild Flex and Seal or Sika Sikaflex 11FC in white or off-white
• Width: 6 to 8mm bead, tooled concave
• Cure time: 24 hours before overpainting with the top coat

Without this sealant step, even the best paint system will crack at the frame junction within twelve to eighteen months of application, admitting water and initiating the cycle of failure all over again.

Oil Gloss vs Modern Water-Based Alternatives

This is the most frequently debated question in front door decoration. The debate is now largely resolved by the improvement in water-based hybrid alkyd products, but there are still conditions where traditional oil gloss is preferable.

Traditional oil-based alkyd gloss (Farrow & Ball Full Gloss, Dulux Trade Gloss, Johnstone's Oil Gloss):

• Dry time: 16–24 hours between coats
• Full hardness: 14–21 days
• Advantages: exceptional levelling and flow, deep gloss depth on well-prepared timber, very hard final film
• Disadvantages: yellowing of whites and light colours over time (significant on a north-facing door with no UV bleaching), solvent odour during application
• Best for: south or west-facing doors in direct sunlight where UV prevents yellowing; colours in the dark navy, black, green and red range where yellowing does not matter

Water-based hybrid alkyd gloss (Little Greene Intelligent Gloss, Johnstone's Aqua Water Based Gloss, Dulux Trade Satinwood):

• Dry time: 2–4 hours between coats
• Full hardness: 7 days
• Advantages: no yellowing, faster recoat, low odour, easier tool clean-up
• Disadvantages: slightly lower levelling ability on imperfectly prepared surfaces (brush marks more visible if application technique is poor); slightly softer final film than oil in the first few weeks
• Best for: any pale or white colour; north-facing doors; situations where odour during application matters

For front doors we prime with a solvent-based primer (Dulux Trade Wood Primer and Undercoat oil-based, or Bedec Stabilising Solution) regardless of whether the top coat is oil or water-based. A solvent primer penetrates timber fibres more effectively than water-based primer and provides a better anchor coat.

System for a front door using water-based topcoat:

1. Bare timber → Bedec Stabilising Solution (allow 4 hours)
2. One coat Dulux Trade Wood Primer (oil-based, allow 16 hours)
3. One coat Dulux Trade Undercoat (oil-based, allow 16 hours)
4. Light sanding at 240 grit, tack cloth
5. Two coats Little Greene Intelligent Gloss (4 hours between coats)

Colour Guide for Period London Front Doors

Period front door colours in London are largely dictated by local convention:

• Belgravia and Chelsea — black gloss is essentially mandatory on Cubitt estate and Cadogan estate properties, though some conservation areas allow dark navy or racing green
• Islington and Hackney Victorians — more latitude; deep heritage colours such as Little Greene's Basalt, Farrow & Ball's Hague Blue and Jitney are widely used
• Edwardian semis across outer London — red, green and black are all traditional; brighter colours (yellow, bright blue) are increasingly common and acceptable in most conservation areas
• Conservation area rules — always verify with the local planning authority before using a colour that differs significantly from established street character

The question we are asked most often: should the door match the windows? In a period property, the front door and window frames are traditionally different — the door is the statement and the windows are a supporting element. They should complement but need not match.

Get a Quote for Your Front Door

A professionally prepared and painted period front door transforms the appearance of a London property and protects it from weather damage for years. Request a free quote or contact our team to discuss your front door.