How to Deal with Cracks, Holes and Flaky Paint Before You Start

A fresh coat of paint can completely transform a room, but only if the surface underneath is properly prepared. Painting over cracks, holes, or flaky paint without fixing them first will almost always lead to disappointing results. The good news? With the right prep, you’ll end up with smooth, durable walls and a professional-looking finish. Here’s what you need to know before you pick up a brush or roller.

Before you even open a paint tin, take time to check your walls in good natural light. Look out for:

• Hairline cracks

• Larger settlement cracks

• Nail or screw holes

• Areas where old paint is flaking or peeling

• Water stains or damp patches (which should be fixed before painting)
  
  

Spotting issues early helps you plan what products and tools you’ll need.

Small cracks (such as hairline ones) can usually be filled with a flexible filler. Apply with a filling knife, smooth over, and once dry, sand it flat.

Larger cracks may need a little extra attention. Widen them slightly with a scraper to ensure the filler adheres properly, then fill, allow to dry, and sand smooth. For structural cracks or recurring movement, consider using a flexible decorator’s caulk.

Small nail or screw holes can be filled with standard filler. For bigger holes, use a lightweight filler that’s designed for deeper repairs. Apply in thin layers if needed, letting each one dry before adding more. Once dry, sand until flush with the surrounding wall.

Top tip: Always dust off the area after sanding because leftover dust can stop new paint from sticking properly.

If old paint is peeling or flaking, don’t try to paint straight over it. It will keep lifting and ruin your finish.

• Scrape away any loose paint with a paint scraper or stiff brush.

• Sand the edges of the remaining paint so the wall feels smooth and blended.

• For stubborn areas, you may need to use a chemical paint remover or heat gun, but always follow safety instructions carefully.
  
  

Freshly filled areas are porous and can absorb paint unevenly, leading to “flashing” (patchy sheen differences). Apply a suitable primer or mist coat over repairs to ensure even coverage when you apply your topcoat.

If cracks or flaky paint are linked to damp, leaks, or mould, resolve these issues first. Painting over them won’t fix the problem and will cause paint to fail again. Use a stain-blocking primer to seal any water stains once the underlying issue has been sorted.

Run your hand lightly over the wall. It should feel smooth, with no raised edges or rough patches. Only once everything is filled, sanded, and primed should you move on to painting.

Preparation might feel like the slow part of decorating, but it makes all the difference. By properly repairing cracks, holes, and flaky paint before you start, you’ll achieve a smooth, long-lasting finish that looks every bit as good as a professional job.