Scraping and repainting a blistered area is only temporary if the source of moisture continues.
Possible causes
- A clean-water or waste-pipe leak
- Water entry from a roof or external wall
- Heavy condensation in kitchens and bathrooms
- Painting onto a damp surface
- Unsuitable primer or poor surface preparation
How can you distinguish the source?
Observe whether the mark changes with rain, water use or air-conditioning. Its position and nearby plumbing points provide useful clues.
Correct sequence
Resolve the moisture source, allow the surface to dry, remove loose layers, repair and prime as needed, and apply paint last.
