The root of all interior peeling paint is poor adhesion to the previous surface. Here are the ten most common causes of poor adhesion.

1. Peeling often gets a foothold from water getting under the paint. Bathrooms are a major place to look for the water’s source, but there may be other issues with the house such as excess humidity or a leaky roof. Water is the cause of most peeling issues. Even if water damage cannot be seen, moisture could still be wreaking havoc.
2. Inadequate cleaning of surfaces before painting will cause paint to peel. A coat of paint applied over a dirty wall is almost guaranteed to peel or crack down the road. Latex is especially vulnerable to dirt.
3. Incompatible paint layers will cause peeling paint. For example, when latex-based paint is used to cover a previous paint job that used oil-based paint, peeling will occur. (It’s usually okay to paint over latex with oil-based paint.)
4. One possibility is simply age – paint does not last forever.
5. Sometimes an incorrect primer is used, or the problem could be no primer at all.
6. Sometimes paint goes bad before being used. For instance, if left in an unheated garage over winter, paint could freeze. After thawing, it won’t have the same performance abilities.
7. Some painting experts contend that inferior paint brands can prematurely fail. Others say that while professional painters have their own brand preferences, all major brand-name paints meet quality standards which are quite adequate when applied properly. Personally, I don’t think all brands are the same even when some are expensive. Research your paint before buying and get the best you can afford.
8. When too many paint coats are added to a wall over the years, the weight of all the paint can cause stress, and gravity eventually pulls everything down and off.
9. Sometimes paint over new wood, even if you think it’s dry, will prematurely peel because the paint degrades from interaction with the wood’s natural oils leaching out. Cedar is especially vulnerable to this. Wood that is not cured enough can also have too much moisture present for good adhesion.
10. While water and moisture are the most common causes of peeling, the opposite can also be true – excessive dryness can lead to peeling paint.

These are the 10 most common causes of interior peeling paint. Knowing this information can help your next paint job go much better for you.