Lime burn
Lime burn is a condition that occurs when the alkalinity in fresh masonry causes the breakdown of the paint binder, resulting in colour loss and overall deterioration of the paint film. Solventborne or alkyd paints, and vinyl-acetate-based acrylic paints are vulnerable to alkaline attack if applied over fresh masonry. Where possible, avoid the use of these products on masonry.

Fresh masonry is likely to contain lime (calcium hydroxide). Until the lime has a chance to react with carbon dioxide from the air, the alkalinity of the masonry remains so high that it can attack the binders of unsuitable paints.

To avoid lime burn, fresh masonry surfaces should be coated in Resene Limelock to lock in any free lime present in the substrate.