How to Repair Chipped Edges on Walls

Chipped edges are everywhere. External corners on walls, plaster returns around door and window openings, edges along ceiling lines. Any exposed edge takes knocks - furniture, tools, ladders, general site traffic. The damage is usually localised but it is always visible, especially once the wall is painted and the light catches it. Here is how to rebuild chipped edges cleanly and get them back to a sharp, straight line.

Step 1: Prep - Clean Up and Stabilise

Remove any loose or crumbling material from the damaged edge. Use a scraper or filling knife to clean back to solid plaster. Do not try to save material that is barely hanging on - it will just come away under the filler and the repair will fail.

Brush off all dust and debris. If the exposed plaster is porous or powdery, apply Wall Hardener to stabilise the surface. Rub your hand across the area - if it comes away dusty, treat it. Apply with a brush and let it dry for a minimum of 24 hours.

Step 2: Fill - Rebuild the Edge

Mix your chosen powder filler with water to a smooth, lump-free consistency. Stick to the mixing ratio on the pack - that gives you the consistency you need to build up an edge.

Using a filling knife, apply the filler firmly to the damaged edge, pressing it into the substrate to get a solid bond. Build it up to match the original edge profile. On external corners, work both faces in the same pass, drawing the filler out from the corner on each side so the two faces meet in one clean line.

For a straight external corner, use the flat of your filling knife or a straight edge against the adjacent face as a guide while you build the filler up on the damaged side. This helps you recreate a clean 90-degree edge without having to shape it freehand.

For curved or moulded edges like plaster returns, build the filler slightly proud, then shape it back once it has set - cutting the surplus away with a trowel or sandpaper until the profile follows the original line, much as you would dress back a timber repair. Use the undamaged sections on either side as your guide.

Once the filler has set, sand back to refine the edge. On straight corners, wrap sandpaper around a flat block and work along the edge to keep it crisp. On curved profiles, use a flexible sanding pad to follow the contour.

The repair is now complete.

Step 3: Finish - Smooth and Refine

For a premium finish and seamless repair, apply a finishing product over it and feather it out across the surrounding surface. On most edge repairs a well-sanded filler is enough.

Let the finish coat dry, then lightly sand. The edge is now sharp, straight, and ready for decoration.