Why Is My Paint Peeling?

Peeling, flaking or blistering paint is a symptom, not a diagnosis. The same-looking peel can come from very different causes, and each needs a different fix. Repainting over it without knowing why usually means it peels again.

Possible causes

Guidance from many sources groups the causes of peeling into three broad categories. Any of them is possible:

• Moisture: paint applied over a damp or still-drying wall, or water reaching it later.
• Inadequate preparation: paint applied over dust, loose old paint, an unsound or powdery surface, or a glossy surface that wasn't dulled.
• Coating incompatibility or failure: for example water-based paint over an old oil-based finish that wasn't prepared.

FinishGrid can't tell you which one applies to your wall. Someone looking at the wall in person can.

Rule out moisture first

Moisture is checked first because paint can't fix it. Peeling near the bottom of walls, peeling with white salty deposits, or peeling near bathrooms, kitchens or pipes are signs worth investigating, though none is proof. If there is damp or a leak, the area is on hold until the source is fixed and the wall has dried: see Damp Walls Before Painting: What to Do First.

If moisture is ruled out

With moisture ruled out, peeling becomes a preparation job. All loose and flaking paint is removed, by scraping or sanding, back to a sound edge. Then the remaining surface decides the next step:

• Firm and sound: fill and smooth the edges and any defects, then repaint.
• Chalky, powdery or crumbly: it needs a penetrating primer before emulsion.

Both are covered in Painting Over Old Paint: How to Prepare the Surface.

If peeling keeps coming back

Peeling that returns after repainting often points to a cause that hasn't been dealt with, frequently moisture, though not always. Before repainting again, have the cause investigated. Moisture-resistant paint on its own doesn't fix a moisture problem.