Why is my paint peeling?

There are several reasons why paint could be peeling. One reason is poor prep work and painting over a dirty surface. Most paints do not stick well to dirt, grease, and oil so the surface needs to be wiped or washed down prior to painting.

Another reason for peeling is using the wrong paint for the surface being painted. For instance, smooth or glossy surfaces are unable to form an adhesion to certain paints and require a primer so paint can adhere properly.

Different types of paint being applied to the same surface can cause peeling. Oil-based paints do not work properly when applied over latex ones and vice versa. Make sure you’re consistent with the paint that is being applied.
Water is the primary cause of flaking or peeling paint, especially on bathroom walls and ceilings, as well as on exterior walls. When water penetrates through the coats of paint, it causes the layers to separate and detach from the surface. This results in bulging, cracking, and finally, peeling.

The water can originate from a leaking roof, gutter, flashing, or soffit. It can also be the result of a permeable wall allowing water to penetrate from or to the inner surface, or even from splashes of water in the washroom.