Using a contractor from out-of-state
I have been doing this for a long time, and I really believe that the only reason the state (any state) cares, is that they get any monies they have coming to them.
It is infinately more important that you do the following:
Have the proper type of roof specified for your particular situation.
Have the proper details for your situation.
Make sure the contractor is well versed in the application of that roof. Just because he can do asphalt shingles dosent he can do BUR.
If you ask him what NRCA stands for and he dosent know, run.
As long as he has liability insurance he should be OK
There is always the consideration of maintenance. No contractor likes to maintain a roof that he did not install, and I dont blame them.