Was the previous job a tear-off, or were the new shingles installed right over the old?
Typically, building codes allow ONE reroof by going over, but don't allow more than two layers of shingles on the roof. Not surprising -- shingles weigh around 4 to 5 pounds per square foot, so pile up a bunch of layers and you use up the safety factor in the rafters (or trusses) pretty quickly. And a second layer never lasts as long over an old roof as it would if the same shingles were laid down like a new roof.
And, lastly, if you expect to be in the house for awhile, stripping two layers of shingles is a female dog of a job, so any money you save today will be blown in demolition costs when the next reroof comes along and the roofer has to take off two layers.
I'm just really skeptical about someone who says he'll do the work for whatever (unknown, indeterminate) amount the insurance company will pay. How do you know what you're going to get? Does his non-price include a style and grade of shingle you'd want on your house? Does his price include a proper underlayment? Does his proposal include disposing of all the old roofing? Is he offering shingles with a 15-, 20-, 25-, or 30-year warranty? Is it a brand you've even heard of?
My grandfather used to say that, "A good worker knows the value of his work." Someone who wanders in and says he'll do it for whatever doesn't seem to be someone who knows the value of his work. (Or ... maybe he does.)
There's only one layer on there, so the previous was a tear-off. That's what I'd want, too. I've been up in the attic a lot, and the wood up there is pretty lightweight.
As for the roofer, he's just fishing for work, or that's the other roofer's opinion. If he gets an adjuster to agree, then he got a job. If the adjuster doesn't agree, he doesn't get a job. But I get nicked for trying to file a claim.
