How to Prepare Woodwork for Painting in London Homes

Why Preparation Defines the Finished Result

Ask any professional decorator what separates excellent paintwork from mediocre paintwork and the answer is always the same: preparation. In London's period homes — from Georgian townhouses in Belgravia to Victorian terraces in Fulham — the woodwork carries a heavy decorative burden. Skirting boards, architraves, window frames, doors, dado rails and picture rails all demand a smooth, durable paint finish that withstands daily wear.

No paint, however premium, can compensate for poor preparation. Skipping steps leads to paint that chips, flakes, cracks and discolours within months rather than lasting the years it should.

Step 1: Assessment

Before sanding a single surface, assess the condition of the existing paintwork and timber:

• Is the existing paint sound? If it is firmly adhered with no flaking or bubbling, you can paint over it after proper keying. If it is failing, more extensive preparation is needed.
• How many layers exist? Heavy paint build-up obscures moulding profiles and creates an uneven surface. On woodwork in Kensington and Chelsea homes with decades of repainting, stripping may be the better option.
• Is there any timber damage? Look for rot, woodworm holes, splits and cracks. These must be repaired before any paint is applied.
• Is there bare wood exposed? Bare timber requires priming — you cannot apply topcoat directly to raw wood and expect it to last.

Step 2: Cleaning

Woodwork accumulates dirt, grease and grime, particularly in kitchens, hallways and around door handles. Wash all surfaces with a sugar soap solution and rinse with clean water. Allow the woodwork to dry thoroughly before proceeding.

This step is often skipped by DIY decorators, but paint adhesion depends on a clean surface. In London kitchens and bathrooms, where airborne grease and moisture are present, cleaning is especially important.

Step 3: Removing Loose Paint

Where existing paint is flaking, bubbling or cracking, it must be removed back to a sound edge. Use a scraper for flat surfaces and a shavehook for moulded profiles. The goal is not necessarily to strip to bare wood (unless the paint build-up warrants it), but to remove all loose material so the new paint has a stable foundation.

For particularly stubborn areas, a heat gun or chemical stripper may be needed. On properties in Westminster and Mayfair where lead paint is a possibility (any pre-1960s paintwork), take appropriate precautions — wet sanding, HEPA vacuum extraction and proper disposal of waste.

Step 4: Sanding

Sanding serves two purposes: it smooths the surface and creates a mechanical key for the new paint to grip.

For previously painted woodwork in sound condition:

• Sand with 120-grit paper to key the surface
• Follow with 180-grit to smooth any scratches
• Use a sanding block on flat surfaces for even pressure
• Use folded paper or a profiled sanding block for mouldings

For bare wood or stripped surfaces:

• Start with 80-grit to smooth rough timber
• Progress through 120-grit and finish with 180-grit
• Always sand in the direction of the grain to avoid cross-grain scratches

Sanding tips:

• Wrap sandpaper around a pencil or dowel to reach into narrow moulding profiles
• A flexible sanding sponge works well on curved surfaces like handrail profiles
• Always dust off thoroughly after sanding — a tack cloth removes the fine dust that a brush misses

Step 5: Filling

Once sanded, fill any imperfections:

• Small cracks and nail holes: A fine surface filler applied with a flexible filling knife, slightly overfilled and sanded flush once dry
• Larger gaps and cracks: A two-part wood filler provides a harder, more durable repair
• Gaps between woodwork and walls: A flexible decorator's caulk applied with a sealant gun and smoothed with a damp finger. Caulk is not sandable, so apply neatly
• Deep rot repairs: Cut out the affected timber, treat the surrounding area with a wood hardener, and rebuild with epoxy wood filler

Allow all fillers to dry completely before sanding smooth. Check your work by running a hand across the surface — your fingertips will detect imperfections that your eyes miss.

Step 6: Priming

Priming is essential on bare timber and advisable over filled areas:

• Bare softwood (common in Victorian and Edwardian joinery): Apply a wood primer. Oil-based primers offer the best sealing properties; water-based alternatives are quicker drying and lower odour.
• Bare hardwood: Some hardwoods contain oils that can inhibit paint adhesion. An aluminium wood primer provides a reliable barrier.
• Knotty timber: Apply a shellac-based knotting solution to resinous knots before priming. Without this step, resin bleeds through the paint and leaves brown stains — a common problem on pine doors and skirting boards across London homes.
• Filled areas: Spot-prime any filled sections to ensure even porosity before topcoating.

Step 7: Undercoat

An undercoat is not always essential, but it provides benefits that justify the extra coat:

• Builds an opaque, even-coloured base for the topcoat
• Smooths minor surface variations
• Improves the final colour richness and uniformity
• Extends the life of the paint system

For a colour change — white over dark woodwork, for example — an undercoat is virtually indispensable. Lightly sand the undercoat with 240-grit paper before applying the topcoat for the smoothest possible finish.

Choosing the Right Topcoat

The topcoat selection depends on the location and the desired aesthetic:

• Gloss: Traditional and hard-wearing, ideal for exterior woodwork exposed to weather. Less fashionable for interiors but still appropriate on period homes in Belgravia and Mayfair.
• Eggshell: A subtle sheen that has become the standard choice for interior woodwork in London. Available in oil-based and water-based formulations.
• Satinwood: Slightly more sheen than eggshell, offering durability with a contemporary look. Popular for skirting boards and doors in modern refurbishments across Chelsea and Battersea.

The Reward of Proper Preparation

Thorough woodwork preparation typically takes twice as long as the painting itself. But the result — crisp, smooth paintwork with clean lines and a professional finish — speaks for itself. Well-prepared and properly painted woodwork in a London home should last five to eight years before needing attention again.

For a quotation on woodwork preparation and painting in your London property, get in touch with our team.