If exterior moisture is the cause, eliminate the source by doing necessary repairs and maintenance:
- Replace caulking;
- Repair roof;
- Clean gutters and downspouts;
- Cut heavy vegetation away from the building.
If moist air is originating from inside, consider installing vents (especially in rooms that tend to get humid such as the kitchen, bathroom and laundry room); attic louvres, exhaust fans and dehumidifiers may also help. Remove all loose paint, or powdery material, with a scraper or wire brush, sand rough surfaces and prime any bare wood. Repaint with an ultra premium quality acrylic paint
- it will provide excellent adhesion and allow water vapour to escape without harming the coating.