Large stucco cracks <br> Unlike hairline cracks, a large stucco crack may indicate a structural problem. Often, large cracks develop at the intersection of vertical walls, at the upper corners of window and door frames, or at joints between wood framing and concrete/brick masonry. Since most large cracks aren’t only wide but also deep, they allow moisture and water to penetrate the building envelope and pass freely through walls. <br> The most “dangerous” cracks are typically wider than 1/16 inc