From HacDC Wiki
Roofing contractors should have full, reliable credentials. Nearly every state makes licensing a requirement, so be sure that they have the proper licensing. In addition, contractors should have full liability insurance in case they have an accident at your home. That way, you will not be liable.
Sometimes a contractor with his own workers can be more cost effective than a contractor who has no workers. More workers means the job will be completed quicker, which means lower costs. If you have a contractor doing it alone, make sure that they aren't inflating the labor costs because of it.
The age of the roof can determine if it needs to be replaced. Most roofs need to be replaced about every 20 years. When your current roof is a second layer on top of your old roof, it has to be replaced after 20 years.شركات عزل اسطح
Like was said before, most homeowners don't know much about roofing. Use the tips here to help you navigate the problems associated with a leaking or damaged roof. Your home and family can only be properly protected if your roof is in good shape.