How to Prepare Walls for Painting

Ask any professional painter what makes the difference between an amateur and professional paint job, and they'll tell you: preparation. Proper wall preparation is essential for a smooth, long-lasting finish. Here's how to do it right.

Why Preparation Matters

Skipping or rushing preparation leads to:

• Paint that peels or flakes
• Visible bumps, cracks, and imperfections
• Uneven colour and coverage
• Shorter lifespan of your paint job

Step 1: Clear and Protect the Room

Before touching the walls:

• Move furniture to the centre of the room or remove it
• Remove wall hangings, switch plates, and outlet covers
• Lay drop sheets to protect floors
• Use painter's tape to protect trim (if not painting it)

Step 2: Clean the Walls

Paint doesn't stick well to dirty surfaces. Clean walls by:

• Dusting: Use a dry cloth or vacuum with brush attachment
• Washing: Use sugar soap solution for greasy areas (kitchens)
• Removing mould: Treat with a mould killer and allow to dry completely
• Drying: Allow walls to dry completely before proceeding

Step 3: Remove Old Paint Problems

Address any existing paint issues:

• Peeling paint: Scrape off all loose paint
• Flaking paint: Sand back to a sound surface
• Glossy surfaces: Sand lightly to help new paint adhere
• Wallpaper: Remove completely or seal properly

Step 4: Fill Holes and Cracks

Creating a smooth surface:

• Small holes (nail holes): Use lightweight filler
• Larger holes: Use plaster or patching compound
• Cracks: Open slightly with a scraper, then fill
• Gaps around trim: Use paintable caulk

Apply filler with a putty knife, slightly overfilling. Allow to dry completely (check product instructions).

Step 5: Sand the Walls

Sanding creates a smooth surface and helps paint adhere:

• Use 120-150 grit sandpaper
• Sand all filled areas smooth
• Lightly sand the entire wall to remove bumps
• Pay attention to edges and corners
• Wipe down with a damp cloth to remove dust

Step 6: Apply Primer

Primer is essential when:

• Painting new plaster or drywall
• Covering stains or dark colours
• Painting over patches and repairs
• Changing from oil-based to water-based paint
• Painting bare timber or metal

Use the right primer for your surface and topcoat. Allow to dry completely before painting.

Common Preparation Mistakes

• Not allowing enough drying time: Filler and primer need to be completely dry
• Skipping the clean: Dust and grease cause adhesion problems
• Inadequate sanding: Leads to visible patches
• Wrong filler type: Different holes need different products
• Forgetting to remove switch plates: Creates messy edges

When to Call Professionals

Consider hiring professional painters if:

• Walls have extensive damage
• There's significant mould or water damage
• Surfaces have lead paint (pre-1970s homes)
• You don't have time for proper preparation