How to Fix Cracking Paint: A Comprehensive Guide by Paintworld

Why Does Paint Crack?

1. Old or Brittle Paint

Over time, older paint loses flexibility. Exposure to UV light, air, and moisture causes the paint film to harden and become brittle, leading to fine cracks known as "alligatoring."

2. Poor Surface Preparation

Skipping proper surface prep—like cleaning, sanding, or priming—reduces the paint’s ability to bond, leading to early failure.

3. Using Incompatible Paints

Applying a rigid or oil-based paint over a more flexible layer (like latex) can cause cracking as the topcoat shrinks and pulls away.

4. Incorrect Application

Painting in very hot or cold temperatures, applying coats too thickly, or not allowing proper drying time between coats can all contribute to cracking.

5. Moisture and Humidity

Moisture behind the painted surface—common in bathrooms, kitchens, or exterior walls—can push the paint film outward, causing it to crack or bubble.

How to Fix Cracked Paint (Step-by-Step)

Here’s how to professionally repair cracked paint and restore a smooth, flawless surface:

•  Step 1: Assess the Damage - Is it just surface-level hairline cracking, or is the paint flaking and lifting? Superficial cracks can often be patched and painted, while deep cracking may require full removal and recoating.

• Step 2: Remove Damaged Paint - Use a paint scraper or putty knife to remove all loose or peeling paint. Don’t leave any weak areas behind—it will compromise the final finish.
  
  Recommended: Iquip Paint Scraper – Heavy Duty

• Step 3: Sand the Surface Smooth - Use medium-grit sandpaper (120–150 grit) to smooth down edges and level the area. This is crucial for avoiding texture differences in your final coat.
  
  Tip: Use a sanding block or orbital sander for larger areas.

• Step 4: Clean the Surface - Dust, grease, and debris can prevent primer and paint from bonding. Wipe the area with a damp cloth or a mild surface cleaner. Allow it to dry completely.

• Step 5: Apply a Quality Primer - Priming is essential to seal the surface, improve paint adhesion, and block stains. Use a primer suited to your surface—masonry, timber, or previously painted walls.
  
  Try: Nu-Tech range of Primers

• Step 6: Repaint Using the Right Paint and Tools - Apply 1–2 coats of high-quality acrylic paint with a professional brush or roller. Let each coat dry fully before applying the next.
  
  Best for Trim: Classic Sash Cutter Brush
  
  Best for Walls: Microfibre Paint Roller 10mm Nap

Common Tools & Materials You’ll Need

How to Prevent Paint from Cracking Again

Fixing cracked paint is one thing—keeping it from returning is just as important. Here are preventive tips every painter should follow: