Let me start this blog by saying I am not a roofer and I am not an underwriter. But I am doing a lot of roof talk these days. Insurance companies are using their technology to take satellite and drone pictures of roofs. They do not like seeing lifted shingles, stained shingles, missing shingles or roofs with tree cover. This is the response of most of the many companies we represent. 
The thing that is shocking most of our clients is the stained roofs issue. A stained roof is often a sign of rot, mold or algae. Over time these stains will degrade the shingles. If your roof has stains, it is best to consult with a roofer and see what can be done. Trimming trees should be a priority. Be careful about power washing; when done wrong, power washing can damage shingles.
Many companies are drawing a line at no new home business with roofs over 15 years old. We are even seeing non-renewals of roofs over 15 years old unless homeowners are getting a roof inspection. Most insurance companies are giving at least 30 days to rectify roof concerns but homeowners do need to act fast if they are given notice because there are no other good options.
These roof review and inspections are due to the increase in claims due to severe weather issues. Insurance policies cover the cost of repairs or replacement. If you have a claim and your roof requires a full replacement this can be very costly.
It is an advantage to work with an independent insurance agency that has options. Kinneman Insurance, with offices in Alexandria, VA and McLean VA, has agents ready to answer your roof questions.