We're in the middle of installing a new gravel roof. Stripping has been done on the old roof, and tomorrow, the main work will be done. How can I as a layperson without any background in the roofing biz inspect and approve the work in the end? It's not like approving a new bathroom! Should I at least wait a day or two before paying the final installment so that I can go up there and look around myself? What should I look for? Thanks.