Blocking occurs when two painted surfaces catch when pressed together – a door sticking to the jamb, for example.
- Not allowing sufficient time for the coating to dry on doors or windows before attempting to close them.
- Using low-quality satin or gloss paints. These generally have poor block-resistance, particularly in warm, damp conditions.
Always use top-quality satin or gloss acrylic water-based paint, and follow the drying times recommended on the paint label.
Acrylic water-based paints generally have better early block-resistance than vinyl acetate co-polymer-based paints or solvent-based paints; however, solvent-based paints develop superior block-resistance over time.