Regardless of which roofing company you choose, if you have a positive feeling about the following issues, then your choice will have been a good one and your installation should be as you expect.

Questions you should ask before you choose:
About Credibility:
Is the company local?
Is the company bonded and insured?
Does the company have references?

About Warranty:
Is the workmanship warranty unconditional? Why not?
Is the warranty transferable?
Are they confident in their workmanship?

About Service:
Is the representative just a salesman or will he be actively involved throughout the entire process?
Should there be any problem, will he be there for you?