Moisture

• When moisture gets into the walls, it expands and contracts the surface of the walls, no matter what they're made of. Some styles of paint, such as latex paint, can adjust to this type of movement, others do not do as well. You're most likely to see this occur around the windows or in rooms that have high humidity such as the bathroom. Resolve this issue by using caulking around the windows, choosing a latex paint and working to lower the humidity in your home.
  
  

Settling

• Homes often settle into the land, which causes the occasional creaks and moans throughout the night. It can also cause crackling in your paint. The repair for this may go deeper than the paint alone, as cracks are likely in the actual wall. Fill these with spackle and sand the area to smooth it down before you add another layer of paint.
  
  

Inadequate Preparation

• It's essential to prepare your walls before you paint them. Dirty or uneven surfaces cause the paint to crackle. Sand uneven areas before you paint and thoroughly clean the walls. Apply a primer coat first, then apply one or two layers of your paint choice, and top it off with a finishing layer. Sanding between every coat and allowing each coat to thoroughly dry is important. Use primers and paints that are compatible with each other.
  
  

Old Paint

• As paint gets older, it starts to lose the elasticity that formerly allowed it to expand and contract with your home. It doesn't necessarily signal major damage. At this point, you can simply resolve the issue by repainting the walls. Prevent this from occurring in the first place by repainting your walls every few years.