A handy guide for preparing walls for painting

The more time you spend on surface preparation, the better your finish will be. Here’s a handy guide for preparing your walls for painting.

Before you get started

Don’t pull out old nails, since you’ll risk damaging your plasterboard. Instead, tap these nails into the wall, then fill the holes with a filling compound.
Crayon and ballpoint pen marks on walls will bleed through a fresh coat of paint. To remove them, rub with a dab of toothpaste on a damp cloth, then rinse with clean water. If some marks still remain, cover them with a stain sealer.
Use a water-based acrylic sealant to fill cracks, scratches and seams in plaster and plasterboard before painting or papering. Apply it with a sealant gun or straight from the tube, and smooth it with a wet fingertip (while wearing protective surgical gloves).
To remove mould before repainting, use a mildew remover or a solution of one part bleach to two parts water. Don’t use a household cleaner; the resulting oily patch may prevent fresh paint from adhering.

Remove all door locks and other fittings.
Cover and tape over light switches and fittings, thermostats and electrical outlets.
Cover the floor with drop sheets.
Wearing rubber gloves, wash all surfaces thoroughly with warm water and dishwashing detergent.
Remove any mildew with a solution of water, bleach and mild non-ammonia detergent.

Remove any loose or peeling paint with your scraper, and feather the edges with sandpaper.
Patch large, uneven areas or deep gaps in the paint with a filling compound.
Don’t try to remove nails; instead, tap them in with a nail punch and fill the holes.
Level any areas you have filled and, once dry, sand them smooth.

Sand glossy surfaces with fine sandpaper, wearing a dust mask and goggles as you work.
Alternatively, use a commercial deglosser according to the manufacturer’s directions on glossy surfaces.
Make sure the room is well-ventilated.

After sanding, brush away all the dust.
Dusting will suffice for most ceilings, but kitchen and bathroom ceilings, which may be greasy or stained with mildew, need special attention.
Spot-clean these surfaces.
You can also buy primers and paints formulated with anti-mould agents in them.

Seal or prime raw wood.
Also spot-prime any newly patched areas on the wall(s) you’ll be painting.
You may want to tint the primer to cut down on the number of finishing coats that will be necessary.
You will want to track your progress as you paint so don’t make the primer exactly the same colour as the finishing coat.
Position a hand-held bulb or bright torch so it shines across the surface you’re preparing to paint.
The light will highlight flaws that aren’t as obvious in daylight.
Take a pencil (not a pen or marker) and lightly circle the spots that need work.
Always wash the walls and ceiling thoroughly before painting.
A simple sugar soap solution will remove most grease and grime.
Dampen your cloth, don’t saturate: that way you won’t have water trickling into electrical outlets.
Rinse the surface and allow to dry before repainting.

Follow this handy guide and you’ll have prepared your surfaces well for a fine finish of paint.