When a home is damaged or destroyed by fire, flood — or for any of a dozen or more different reasons beyond the owner’s control — and the insurance company cuts a check for the repairs, a certain kind of contractor usually does the work.

Restoration contractors move fast — dispatching crews to demo, clean, and dry within hours. If companies such as Belfor — the industry giant — or Giertsen Co. or Mellon Certified Restoration, operate at efficiency levels that leave general contractors envious, it’s because they have to. Insurance restoration is the emergency room of home renovation. If your house is destroyed or damaged, chances are you’re not going to argue about the specifics of fixing it. Immediacy is key to success.

The insurance restoration model differs in other ways, too. These contractors have more than one customer per job: they deal with the insurance company, the mortgage company, and the homeowner. All are clients, in a sense. The contractor doesn’t get paid until the job is done.

Many contractors would love the steady business, but “it’s a whole different set of rules,” says John Allen, owner of the John A. Allen Co., in Jackson, Tenn., who has been dealing with wind, water, and fire damage since he started in insurance repair in the 1980s. “I’ve never had two days alike,” he says.