Blistering and flaking
This may be due to any of the following factors:
- Moisture trapped beneath the surface of the paint film.
- If the paint is applied over a powdery or friable surface.
- Surface contamination such as dirt, oil, and grease.
- Polish residues on the surface, which impair the adhesion of the paint.
- Excessive movement of the substrate, such as joints, imposing stress on the paint film which can result in cracking which in turn lets in moisture, ultimately resulting in a flaking paint film.
- Resins present in knots causing light coloured paints to discolour or even flake. Resin bleed and flaking is a common problem where dark colours are used on south facing elevations. This is because dark colours absorb more heat than light colours.
Putting it right
All loose material will have to be removed back to a firm edge, spot primed with the appropriate Dulux Primer, and then recoated with the appropriate product. If large areas are involved it will be best to totally strip the surface back to a bare surface and start again.