How to Paint a Room Properly: The Preparation Nobody Does

Painting is easy. Everybody can move a roller. The reason home-painted rooms look home-painted is that the preparation stage is boring and gets skipped.

Here is the full sequence, including the parts that feel unnecessary.

What you need

• Filler and a filling knife
• Sandpaper, 120 and 180 grit
• Sugar soap or a degreaser
• Low-tack masking tape
• Dust sheets
• A 9-inch roller with a medium pile sleeve, plus a 2-inch angled brush
• Paint, plus primer if you are covering bare filler or a strong colour

Time: half a day of preparation, half a day of painting, per average room.

Preparation, in order

1. Empty the room, or as near as you can. Working around furniture doubles the time and guarantees a splash on something you care about. Everything remaining goes to the centre, under a sheet.
2. Fill every hole and crack. Push filler in with the knife rather than smearing across, then scrape flush. Filler shrinks slightly as it dries, so slightly proud is better than flush on deep holes.
3. Sand. 120 grit on the filler, then 180 over the whole wall with light pressure. This is the step everybody skips and it is the one that matters most — it flattens the filler and gives the old paint a key.
4. Wash the walls. Sugar soap and a sponge, top to bottom, then clean water. Walls carry more grease and dust than anyone expects, particularly in kitchens and above radiators. Paint does not stick to grease.
5. Vacuum, then wipe with a damp cloth. Sanding dust in the paint film shows up as texture under a raking light.
6. Mask. Tape edges you cannot cut in confidently — sockets, skirting, window frames. Press the edge down hard with a filling knife so paint cannot creep under it.

Painting, in order

1. Ceiling first. Always. Splashes fall downwards onto walls you have not painted yet.
2. Cut in the edges with the angled brush — a band about 50mm wide around the perimeter of each wall, around sockets, and along the skirting.
3. Roll while the cut-in is still wet. This is the trick behind an invisible join. If the brushed edge dries before the roller reaches it, you see a texture change forever.
4. Roll in overlapping W shapes, then lay off in long vertical strokes from ceiling to skirting with light pressure. The laying-off pass is what removes roller texture.
5. Let it dry fully before the second coat. Read the tin. Recoating too early lifts the first coat and leaves patches.
6. Remove masking tape while the final coat is still slightly tacky. Dried paint bridges the tape edge and tears when you pull it.

The mistakes that cost a repaint

• Skipping primer over filler. Filler is far more absorbent than paint. Without primer it drinks the topcoat and dries matt, so every repair shows as a dull patch.
• Cheap masking tape. Standard brown or clear tape pulls the old paint off with it.
• Overloading the roller. More paint per pass does not mean fewer passes, it means runs.
• Painting a cold room. Below about ten degrees most emulsions do not form a proper film. Heat the room the day before.

How long it should genuinely take

An average bedroom, walls and ceiling, two coats: one full day if you prepare properly and one full day if you do not, because you will spend the second day fixing it.