How to Prepare a Room for Painting

Why Preparation Makes All the Difference

The biggest mistake homeowners make when painting a room is rushing the preparation. Professional decorators spend far more time preparing than actually painting, and that is the secret to a smooth, lasting finish. Skip the prep and you will see every bump, crack and brush mark.

Step 1: Clear and Protect the Room

Start by removing as much furniture as possible. For items that cannot be moved, group them in the centre of the room and cover with dust sheets. Also cover:

• Flooring with canvas or plastic dust sheets
• Light switches and sockets with painter’s tape
• Door handles and window latches

Remove curtains, blinds and any wall-mounted items such as shelves, mirrors and picture frames.

Step 2: Inspect the Walls

Walk around the room and look closely at every wall. Mark problem areas with a pencil so you do not miss them later. Common issues include:

• Cracks along corners and around door frames
• Nail holes from picture hooks
• Flaking paint from previous coats
• Damp patches that need investigation before painting over
• Uneven plaster or textured areas

Step 3: Repair and Fill

Use a flexible filler for small cracks and holes. For larger gaps, you may need a two-part filler or even replastering. Apply filler with a filling knife, slightly overfilling each hole, as filler shrinks as it dries.

For flaking paint, scrape off all loose material back to a firm edge. If wallpaper is peeling, strip it completely rather than painting over it.

Step 4: Sand Everything

Once filler is dry, sand it flush with the wall using 120-grit sandpaper. Then lightly sand the entire wall surface with a finer 180-grit paper. This creates a key for the new paint to grip and removes any small imperfections.

Sand woodwork too. Gloss paint on skirting boards and door frames needs a proper key to accept new paint. Our carpentry service can repair any damaged woodwork before decorating.

Step 5: Clean the Surfaces

Dust the walls with a dry cloth or vacuum with a brush attachment. For kitchens and bathrooms, wash walls with sugar soap to remove grease and grime. Rinse with clean water and let everything dry completely.

Step 6: Mask Off Edges

Apply painter’s tape along:

• Where walls meet the ceiling
• Around window frames and door frames
• Along skirting boards
• Around light switches and sockets

Press the tape down firmly to prevent paint bleeding underneath.

Step 7: Prime

Primer is essential in several situations:

• New plaster needs a mist coat of diluted emulsion
• Bare wood needs a wood primer
• Stained areas need a stain-blocking primer
• Dark colours being covered with light paint benefit from a white primer

Common Mistakes to Avoid

• Painting over damp patches without fixing the cause first
• Using masking tape that is too old or cheap, leading to bleed-through
• Not allowing enough drying time between coats
• Painting in poor light, which hides missed patches

Professional Painting Services in South London

Proper preparation takes time and effort. If you would rather leave it to the professionals, our painting and decorating team handles every stage from preparation through to the final coat. We work across Clapham, Fulham, Wandsworth, Chelsea and all South London areas.