Foam roof a 2-for-1 deal?

Future-Proof: Navigate Threats, Seize Opportunities at ICNY 2018 | Jan 22-26 at the Marriott Marquis, Times Square, New York

Q: We would appreciate your advice regarding our San Francisco home's roof. We have a 1915 Edwardian with a flat tar-and-gravel roof in one of the "sunny" San Francisco neighborhoods. We've had the home for a dozen years, and while we don't know the date of the last roofing job, my husband thinks it's time to reroof. I would like some insulation on our top floor -- insulation seems an afterthought in the house as a whole -- and my husband is thinking of installing tubular skylights called Solar Tubes to bring light into the two north rooms of the house. There is some blown-in insulation -- not sure how extensive because the access to the attic is via a small space I can barely poke my head into. Last, we'll add a solar-energy system, although we are not sure when. We've gotten several roofing-only quotes, most for typical tar and gravel, and find it hard to differentiate how the work is different from one to the next, except for a quote from a company that wil...