What are good questions to ask a roofer?

Are you licensed and insured? Do you have any references? How long will the job take? What is the warranty? How much will it cost? Is there a deposit required?

What are good questions to ask a roofer? -How long have you been in the business? -Do you have any references I can call? -What is the warranty on your work? -Can you provide me with a written estimate? -When can you start the work? -How much will it cost? -What type of materials will you be using? -Will you be doing the work yourself or hiring subcontractors? -Is there anything I need to do to prepare for the work?