A. Steve Thomas, a stucco industry veteran, responds: I have to admit (even after a phone call to the builder), this one has me stumped. There are several possible causes for the cracking. The prolonged high winds could have caused the finish to craze, but why on just one wall plane? The framing lumber could have been abnormally dry, then "stretched" as it picked up moisture — but ordinarily the 1/2-inch plywood should have prevented cracking. Conversely, the lumber could have been excessively wet, then shrank as it was protected from the rain. But again, the plywood sheathing should have restrained movement enough to prevent cracking. It’s also possible that the 1/2-inch plywood could have been butted too tightly, causing it to buckle at edges and cracking the finish.
Another possibility is that the wind lifted the roof and wall, or caused the wall to rack (not uncommon in garage walls because of the large openings and consequent lack of lateral bracing.) I asked the builder whether impact loads or heavy loads in the attic floor could have played a part, but no such impact occurred, and there’s no floor in...
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