Washington Consumer Checkbook magazine did a comprehensive review of area roofers in their Fall 2004 / Winter 2005 issue. You can buy a copy of the article online. It's well worth the $15.00 before you spend thousands on a new roof. Arlington County libraries have back copies on computer databases. If you ask at the reference desk, they can help you access an old issue. You don't have to be a county resident to use this service.