Painted timber weatherboards – paint chalking

Cause

Weathering, UV light exposure – chalking will be more visible with darker colours

Repair

  • Chalking is the formation of a fine powder on the surface of the paint. It is typically a sign of UV weathering of paint. Chalking happens faster to poor-quality paint and to oil-based paint.

  • Wash the walls thoroughly with a soft brush and mild detergent. Rinse with clean water and leave to dry.

  • Do not use a waterblaster on weatherboard walls – it can lead to long-term damage if it forces water through gaps into the wall assembly.

  • Sand the existing surface, smooth rough edges and remove sharp corners from boards. Brush off all the dust after sanding to leave a clean surface.

  • Repaint with at least two coats of high-gloss or semi-gloss acrylic paint. When applying paint, follow the recommendations in our maintenance guide for painting