From different sources (friends, relatives, colleagues, magazines, going to construction sites and asking questions, etc.) you should make a list of some eligible roofing contractors. By “eligible” you must understand builders about whom you have good recommendations and which are focused on commercial roofing.
Get recommendations about each of the candidates. Respected Dallas commercial roofing company experts advise you to ask: what did they do well? What did they do wrong? How did they fit into the schedule? How did they fit into the budget? What mistakes did they make? Did they follow the plans? Were they constructive? Would you work with them again? Did they have skilled workers?
You want concrete details and not generalities or ambiguous information. Listen to what people are telling you and not what you want to hear.
Go ahead with potential builders that answered satisfactory for you. Check if they are licensed and insured and ask for a detailed estimate of the works and an execution plan. Insist that you do not expect to get a little piece of paper with 3 prices listed on it, but you want everything in detail, both in terms of costs and execution time. Erase from your list those contractors that do not deliver you the estimate within 10 days; if they did not have time for an estimate, they will not have time for construction either.
Compare the estimates of all builders and keep the one you find most convenient. Hire the respective company and make the contract.