Paint Peeling Off The Wall

What's happening?

Peeling — the trade calls it flaking — is adhesion failure. The paint film has stopped gripping whatever is beneath it and is releasing in sheets or curling flakes. Dulux Trade's guidance on flakes, cracks and blisters puts the usual causes as a surface that was not prepared properly, dust or dirt left in place, a surface that was still damp or unstable when painted, or paint applied over a very shiny coat it could never key into. The tell is what comes away with it: if bare plaster shows, the failure is at the wall; if you can see another colour on the back of the flake, the failure is between coats and the earlier layer is the problem. Peeling spreads, because every open edge lets more moisture behind the film.

What usually causes it?

• Painting over a glossy or previously oil-based surface that was never sanded to give a key
• Dust, sanding debris or cooking grease left on the wall before the first coat went on
• Emulsion applied straight onto new plaster with no thinned mist coat, so it sat on the surface instead of soaking in
• A powdery, chalky or friable old distemper or limewash layer that the new paint is stuck to rather than the wall
• Moisture reaching the back of the film from a leak, condensation or plaster that had not finished drying
• Painting in the cold or damp, below the minimum application temperature on the tin's data sheet
• Too many coats built up over decades, so the total film is too rigid to move with the wall

When should you call a painter and decorator?

Call a painter and decorator when the peeling covers more than a patch you can reach from the floor, when the surface beneath is chalky or unstable, when you have stripped once and it has come back, or when you suspect lead or a pre-2000 textured coating. A decorator will identify which layer failed and specify the primer that will hold, which is the part homeowners usually get wrong.

What will the painter and decorator actually do?

• Test the adhesion of the existing coats and identify which layer is releasing
• Strip back to a sound edge using wet methods where lead is possible, and check for textured coatings that need specialist removal
• Wash down, de-nib and make good the substrate, filling and sanding flat where the strip has left a step
• Apply the correct primer or stabilising solution for the substrate — bare plaster, chalky distemper and old gloss each need a different one
• Recoat in the specified number of coats, working within the temperature and recoat times on the manufacturer's data sheet