By Joseph F. Schuler Jr.. It was a surreal day, because part of it was really funny," says Jimmy Waller, of Waller Construction in Lakeland, Fla. "I didn't even think something like this could happen."

But in a subdivision of 2,400 homes, on a street with north and south mirror addresses, and with an absent homeowner, ripping the roof off the wrong house was possible. By 10 a.m., the real client called: "Where are you guys?" At that point, the supervisor knew: They'd stripped the wrong roof. The crew reroofed the first house, finishing the job at 3 p.m. Then, the estimator waited four long hours for the homeowner to return from work.

He was shocked, but the next day the homeowner agreed to sign a liability waiver, refusing to pay anything toward the roof, which Waller estimates at $15,000, between hard costs, project manager time, and attorney fees. Had the homeowner sued, saying Waller Construction had destroyed the home's aesthetic or curb appeal, he could have forced the closure of the company's then-new roofing division.

"The experience taught us we needed to have a system," Waller says. Now, estimators photograph the home. They require someone be home for a preconstruction meeting and again when the job starts. The crew leader calls the office to check in before setup. "In the life and journey of this division, it was a good day," Waller says. "We had to learn the hard way."

The division now does 250 reroofs and 300 repairs a year, always -- always -- at the right address.