How to Prepare Walls Before Painting
The thorough preparation that underpins every smooth, long-lasting paint finish.
Decorators have a saying that painting is ninety per cent preparation, and it holds true. The finish you see is only ever as good as the surface beneath it, and most disappointing results can be traced back to a skipped preparation step.
This guide covers the essentials of getting walls ready, whether they are freshly plastered, previously painted or marked by years of family life. A little method here saves a great deal of frustration later.
What you will need
- Sugar soap
- Sponge and bucket
- Filler and filling knife
- Fine sanding sponge
- Mist coat or primer
- Dust sheets
- Caulk and caulking gun
Protect and clear
Lay dust sheets over floors and furniture, and remove or mask fittings such as sockets and switches. A clear working area lets you move freely and spot defects. Good lighting at this stage helps you see every blemish.
Wash the walls
Clean the walls with a sugar soap solution to lift grease, dust and old grime, working from the bottom up to avoid streaks. Rinse with clean water and allow to dry. Kitchens and rooms with a wood burner especially benefit from a thorough wash.
Fill and make good
Fill cracks, dents and old fixing holes, pressing the filler well in and leaving it slightly proud to allow for sanding back. For gaps where walls meet trim, run a bead of flexible decorator's caulk and smooth it with a damp finger. Let everything dry fully.
Sand smooth
Rub down filled areas and any rough patches with a fine sanding sponge until they are flush and smooth. Lightly abrade glossy or previously painted surfaces to give the new paint a key. Wipe away all dust with a slightly damp cloth.
Prime where needed
Seal fresh plaster with a thinned mist coat and treat stains or very porous patches with a suitable primer. Priming evens out absorbency so the topcoat dries to a consistent finish. Allow the primer to dry before painting.
Final check
Run your hand and your eye over the walls in raking light to catch any missed defects. It is far easier to address them now than after painting. Once satisfied, dust off once more and you are ready for the first coat.