How to Repair Walls

Before painting or decorating walls, it’s essential to repair holes and cracks for a smooth finish while also ensuring no further damage. Our step-by-step guide is here to help you through the process, including finding the right tools and filler products for your job.

What causes cracks in walls?

There are several reasons why cracks or holes may appear in interior walls. Often, it’s due to the plaster shrinking or expanding, which can happen over time with changes in weather; leaking rainwater and damp are some of the most common causes of interior wall cracks.

Holes can also appear in walls when air bubbles are trapped in the plaster, weakening the seal once dry.

If you spot significant cracks or holes in ceilings or load-bearing walls, this could point to more serious structural issues which should be investigated by a professional.

Step-by-step guide to repairing holes in walls

Learn how to fix different types of holes in walls here, whether you’re dealing with a hairline crack or a large hole. Whatever the problem, it’s essential to find the cause and address this before undertaking repairs to prevent further damage.

In addition, you should use the right products and tools for the surface you’re working with. At Dulux Decorator Centre, we have plenty of plastering equipment and fillers from top trade brands, ensuring a quality finish.

How to repair small cracks or holes

Small cracks or holes in plaster walls are relatively easy to resolve. Follow these steps for the best results:

Remove any loose plaster from inside the crack with a knife.

Dampen a paintbrush and apply water to the crack – this slows the filler drying process, preventing shrinking and improving adhesion.

Apply a small amount of filler to a filling knife and spread it evenly across the crack at a right angle (deeper cracks may need a second application once the first is dry).

Smooth the newly filled surface with sandpaper, and you’re ready to redecorate!

How to repair big holes in plaster walls

Large holes require a few additional steps, especially if the plasterboard underneath is damaged. Here’s how to patch up holes in walls:

Cut a piece of plasterboard or wire mesh slightly larger than the hole.

Insert and tie a piece of string through the centre of your plasterboard or wire mesh piece.

Put the piece inside the hole, and use the string to pull it against the inside of the wall.

Apply a first layer of filler around the hole, leaving the string exposed, and wait for it to dry before moving on to the next step.

Cut the string flush with the wall, and apply a second layer of filler over the small hole.

Smooth the newly filled surface with sandpaper and redecorate.

Significant holes in walls may require a complete re-plaster if this technique isn’t suitable. Explore our tips for painting over fresh plaster for a professional, long-lasting result.

The best wall crack repair products

Depending on the surface you’re working with, there are several wall crack repair products to choose from, including:

Interior filler. This general-purpose filler is ideal for patching up small cracks and holes; try Toupret Patch and Repair Quick-Dry Filler, which is suitable for repairs on plaster, plasterboard, cement, concrete, brick and stone.

Joint filler. For larger holes where additional plasterboard has been added, choose Tourpret’s Joint, Skim and Fill Powder to ensure a smooth join; it’s compatible with plaster, plasterboard, cement, concrete, brick and stone.

Flexible acrylic filler. Ideal for filling gaps, cracks or holes between plastered walls and woodwork (e.g. skirting boards or doorframes).

At Dulux Decorator Centre, we also stock a wide range of accessories, essential tools and equipment for wall repairs. From dust sheets to PPE, filling knives, scrapers, plastering tools and paintbrushes, find everything you need for your next job here.