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.

A handy guide for preparing 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.

What you will need

  • Masking tape
  • Plastic drop sheets
  • Rubber gloves
  • Clean rags and sponges
  • Dishwashing detergent and warm water
  • Household bleach
  • Mild, non-ammonia detergent
  • Paint scraper
  • Abrasive paper
  • Filling compound
  • Filling knife
  • Dustpan brush
  • Primer or sealer
  • Dust mask, goggles and respirator
  • Hammer and nail punch (if required)
  • Deglosser (optional)

1. Wash it down

  • 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.

2. Level the surface

  • 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.

3. Take the shine off

  • 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.

4. Sweep it clean

  • 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.

5. Prime it up

  • 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.

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