Identification

• Peeling and cracking paint inside your home is typically caused by a moisture problem. When moisture is constant, the humidity is higher than normal. When moisture moves through your ceiling, it eventually damages painted surfaces. If moisture and high humidity remain a problem, mold may begin to grow. Mold growth is caused by fungal spores landing on areas in your home that remain damp, where they germinate. Homeowners who have cracking or peeling paint should consider painting the ceiling with a moisture barrier to prevent further damage.
  
  

Uses

• According to the United States Department Of Energy (DOE), a moisture or vapor barrier is a material that reduces the rate that moisture moves through surfaces. Vapor barriers are often used in damp basements, on ceilings, slab foundations and walls. When a vapor barrier is used in conjunction with exhaust fans, it can reduce moisture damage inside your home. Sealing all areas in your kitchen that are leaking air is another way to reduce moisture. Check under window sills and door thresholds for gaps that can let humid air inside. Caulk any area that allows air into your home.
  
  

Types

• There are a variety of paints that are labeled as a vapor or moisture barrier. However, the DOE states that adding numerous layers of paint to your kitchen ceiling is also an effective vapor barrier in most homes. Only extremely cold climates need more protection from moisture. When choosing a paint to use as a vapor barrier, consider a glossy paint because it is a more effective vapor barrier than flat paint. Acrylic paints work best as latex paint does not provide adequate moisture control. Adding multiple layers of paint will work to keep moisture from damaging your painted ceiling.
  
  

Considerations

• At one time, it was thought that only paints with a low permeance rating were effective vapor or moisture barriers. The permeance rating is the measurement of a material's ability to slow down the diffusion of water vapor. Paints have their permeance rating listed on the label. However, choosing a paint with a high percentage of solids and applying many layers of paint to add thickness are just as effective as paints labeled as vapor barriers.