Harry Whitver
Cement shrinkage can lead to fine surface cracking in the color …
Old-fashioned three-coat stucco is still popular in many markets, especially on high-end homes. Successful stucco applications depend on the skill and care of experienced applicators; without the right touch, you risk inconsistent color or finish cracking.
To minimize cracking, you have to work with the material’s natural characteristics. The trick is to vary the cement mix among the different coats: the hard base coat, or “scratch coat,” which should be allowed to crack as it sets up and cures; the “brown coat”; and the final “color coat,” which uses softer, more flexible formulations. The base coat has the highest proportion of cement for strength; subsequent coats use less cement and more fine sand.
Some fine cracking can still occur in the upper coat. You could trowel more wet stucco into the cracks, but that quick repair tends to show. Instead, wet the area and apply dry cement to the crack for a near-invisible fix.
