Blistering Paint

Blistering may be due to temperature or moisture

When paint does not bond or adhere to the underlying surface, then bubbles or blisters may appear. This may occur with newly painted surfaces or when there is moisture involved.

They may pop to the touch and usually are dry on the inside of the bubble; however, they may occasionally contain moisture.

Overall, blistering or bubbles is often associated with moisture in one way or another, but can be caused by other issues.

Common causes

• Improper or insufficient surface preparations. Applying paint over a dirty, damp or oily surface.

• Applying the top coat to soon over the primer before the primer has had sufficient time to dry properly.

Exterior

• Heat blistering: usually occurs on hot days; painting in direct sunlight on hot days or on very warm days when the surface that is too warm.

• Moisture blistering is usually water migrating through an interior wall to the exterior.

• Placing an oil-based or alkyd paint over a damp or moist surface, especially on rainy or humid days.

Interior

• Applying the paint in high humidity locations, such as, bathrooms, kitchens, and basements.

• Hot days – painting a house when the temperature is high, may cause the paint to dry too fast, thus blistering. Also, poor ventilation while painting and during the curing process

Tip: If blistering continues to occur on the exterior a year after the paint has been applied; try cutting back excessive shrubbery and plants near or against the house. A second tip, is do not mix brands between the primer and top coat, for they may not be chemically compatible.

Who to consult? 

Many homeowners take on painting projects both indoors and outdoors themselves. Handymen and professional painters are also equipped to manage these tasks. Typically, professional painters execute these jobs with greater efficiency, expertise, and speed.