enoughisenough: I am curious to know just how that is handled...
I don't know for certain 100%, but my understand is that -at least in the USA- the insurer has to approve of the contractor so that they don't end up paying for substandard work. The WTS may contact the insurer and convince them that they can handle the work, but I have no idea how that process goes. But if they're cashing the checks, I'm pretty sure that is what happens.
Well, I guess another way they can do it is for the homeowner to get an estimate and have the insurer cut a check, which they then turn over to the WTS. But I would assume that the insurer would be the one providing the estimate and would also need to inspect the home afterwards to make sure their money was spent properly (they are, after all, still insuring the home against future damage). But I guess it's possible that the homeowner can ask to use their own contractor and the insurer allows it, as long as the repair is up to their standards when they inspect it.
But yes, the end result is that the WTS sends volunteers to provide free time and labor, and the organization gets the money. I'm not sure who pays for the materials, but I assume the WTS does. They still come out well ahead, since labor is a large part of the cost and can be variable, while material costs tend to be more stable and predictable.