Steam

• Steam and paint do not mix well. The steam can have a debilitating effect on paint surfaces, causing moisture to build up and compromise the integrity of the paint itself. And, since paint in showers is exposed to steam far more than in any other area of the house, it's only natural that the paint will sustain more heat damage than other areas. Steam will also aggravate many other problems.
  
  

Improper Preparation

• Some paint jobs are doomed from the beginning, regardless of the location. If you fail to prime the surface before painting, neglect to clean the surface properly, or forget to sand down the previous paint job before painting over it, the paint may have a difficult time adhering permanently to the surface. This is especially true in a shower where moisture and heat will assault the paint job on a regular basis.
  
  

Wrong Paint

• Some paint fares better in certain areas than others. High-gloss paint, for instance, is often preferred in moisture-heavy areas as the gloss makes the paint far more resistant to moisture. Attempting to paint over old lead-based paint with latex-based paint will almost always result in peeling thanks to the chemical reactions between the two different paints. Lead-based paint simply cannot provide an effective bonding surface for latex, and will not hold it in place especially in high-moisture areas.
  
  

How to Fix It

• Unfortunately, the only way to fix a peeling paint job is to scrape it off and start all over. Peel or scrape away the existing paint job and do it right the second time around. Sand down the surface, apply a good base coat or primer and choose the right paint for the job --specifically, high-gloss paint with the same base (oil or water) as the primer. The steam will still hit the paint, but is much less of a problem if the job is done correctly.