In climates subject to wide fluctuations in temperature, however, masonry exteriors are prone to an additional problem that conventional paint – even top quality products – can’t always handle: water penetrable surface cracks. In the past, preventing the appearance or re-appearance of these cracks has not always been easy. But now, that has changed. The reason: a generation of paints called elastomeric wall coatings (EWCs) that have the ability to actually bridge and cover the cracks that can develop in a masonry wall.
EWCs are specially formulated with binders that provide far greater flexibility and elasticity than those used in conventional paints. As a result, an EWC can stretch to span a crack as it expands due to change in temperature. It returns to its original shape without wrinkling when the crack contracts. EWCs perform well only when applied in a thick film. A thick film ensures that there is enough material to span a crack at its widest, and helps maintain the desired appearance.