You can buy the best paint in the world, but if you skip the preparation, the finish won’t last six months. As a painter working across South London — from the Victorian terraces of SE17 to the modern flats in Brixton — I see the same mistake over and over: people rush to open the paint tin before the wall is ready. Here’s exactly how to do it right.
Why Wall Preparation Matters
Fresh paint won’t hide bumps, cracks, or grease. It highlights them. On older London properties — many dating back 100 years or more — walls often have layers of old wallpaper paste, nicotine stains, and decades of fillers. Skipping prep means your new paint will flake, peel, or look uneven within weeks.
Tools and Materials You’ll Need
Before you start, gather: sugar soap (or mild detergent), a sponge and bucket, filling knife, ready-mixed filler, 120-grit sandpaper, a sanding block, dust sheets, masking tape, and a good-quality primer. You can find everything at any hardware shop on Walworth Road or in Dulwich.
Step 1: Clear the Room
Move furniture to the centre and cover with dust sheets. Take down curtains, pictures, and light switch covers. Mask off skirting boards, window frames, and sockets with tape. The more you protect now, the less you clean later.
Step 2: Clean the Walls
Wash every surface with sugar soap and warm water. Pay special attention to kitchens and bathrooms — cooking grease and soap residue are paint’s worst enemies. In South London flats where ventilation is often limited, bathroom walls can hold surprising amounts of moisture and product buildup. Rinse with clean water and let dry completely.
Step 3: Fill Cracks and Holes
Go around the room with a filling knife and ready-mixed filler. Fill every nail hole, hairline crack, and dent. For larger cracks — common in period properties around Kennington and Camberwell — use a flexible filler that moves with the building. Let everything dry, then check again: filler shrinks, so a second pass is normal.
Step 4: Sand Smooth
Once the filler is dry, sand every patch flat with 120-grit paper. Then give the entire wall a light sand — this “keys” the surface so paint grips properly. Wipe down with a damp cloth to remove dust. Never paint over sanding dust; it forms a gritty layer that ruins the finish.
Step 5: Prime Bare Surfaces
If you’ve exposed bare plaster — common after removing old wallpaper in London homes — you must prime before painting. Unprimed plaster sucks moisture out of paint, causing it to dry patchy and weak. Apply one coat of watered-down emulsion (a “mist coat”) or a dedicated primer. Let it dry for at least four hours.
When to Call a Professional
Preparation takes time — often longer than the painting itself. If your walls have extensive cracking, damp patches, or peeling layers of old paint, it’s worth getting a professional assessment. A proper prep job on a three-bedroom flat across areas like Peckham, Vauxhall, or Stockwell typically saves you repainting again in two years.
Need a hand with your next decorating project? Get in touch with Paolo for a free quote — covering SE17 and all South London postcodes.