Thermal cracking on central-Brevard block
A Melbourne block wall heats hard in afternoon sun and cools fast after dark, every day of the year. Stucco is rigid, the wall behind it keeps moving, and the finish eventually gives at its weak points — the hairlines you see fanning from window heads and corners. They are rarely structural, but every open hairline drinks wind-driven rain, and moisture behind stucco is the expensive part. Opened, filled with elastomeric material and texture-matched, they stay closed.