A well made flat roof (for your low pitch) should last close to 50 years. They're commonly more expensive but much more durable than pitched roofing. I'd proba

A well made flat roof (for your low pitch) should last close to 50 years. They're commonly more expensive but much more durable than pitched roofing. I'd probably consult with the solar folks before getting your roof redone though. You'll probably save money if you make sure the roofers and the solar installers are coordinating correctly before either goes to work.