How To Fix Paint Blistering
Stop vapor penetration and blistering
How To Fix Paint Blistering
Homeowners and property managers do their utmost to promote the durability, and the good looks, of their buildings. New paint is an easy way to achieve this goal. However, paint is susceptible to many serious forms of damage that include the issue known as blistering. Residential and commercial property owners who keep these basic tips in mind can prevent or fix blistering paint.
Paint Blistering
What Is It?
Moisture retention is the driving force behind most outbreaks of blistering. Expanding vapor causes loss of paint adhesion and bubbling. Blisters can form on the interior or exterior walls of buildings.
Kitchens and bathrooms are interior sources of moisture that can cause paint to blister.
Externally, moisture from humidity and rainwater can seep into untreated wooden end-joints or other exposed areas of the woodwork. Blisters can form if painters allow excessive amounts of moisture to accumulate on freshly painted surfaces.
Hot weather conditions can cause the thinners mixed with fresh paint to vaporize and expand outwards, leading to blistering.
Paint Blistering
How To Fix It
To mitigate the effects of existing blistering damage, follow this 3-step process:
- Remove areas of paint separation (blisters) with sanders*, brushes, or scrapers.
- Clean the exposed surfaces, sand* them, and prime them with high-adhesive alkyd primers.
- Once the primers cure, re-paint the previously-bubbled surfaces following the blistering prevention guidelines below.
*WARNING! If you scrape, sand, or remove old paint, you may release lead dust or fumes. LEAD IS TOXIC. EXPOSURE TO LEAD DUST OR FUMES CAN CAUSE SERIOUS ILLNESS, SUCH AS BRAIN DAMAGE, ESPECIALLY IN CHILDREN. PREGNANT WOMEN SHOULD ALSO AVOID EXPOSURE. Wear a properly fitted NIOSH-approved respirator and prevent skin contact to control lead exposure. Clean up carefully with a HEPA vacuum and a wet mop. Before you start, find out how to protect yourself and your family by contacting the USEPA National Lead Information Hotline at 1-800-424-LEAD or log on to www.epa.gov/lead.
Paint Blistering
How to Prevent It
Before Painting:
- Ensure that wooden building components are well-protected from moisture.
- Install water-vapor barriers on the interior surfaces of exterior walls.
- Treat any exposed areas with water-repellent caulk.
- Include adequate ventilation exhaust fans in high-humidity areas.
When applying exterior paint:
- Apply paint when the outside weather conditions are temperate.
- In hot weather, paint surfaces after sun-exposure, not before.
- Avoid painting early in the day when condensation may form on fresh coats.
- Ensure that glazing around windows and flashings are in solid condition.
