They don't assign much, if any, difference in value for a 10 year old shingled roof versus a 20 year old one. 

If I was your buyer, I would have liked to see an accent color on the shingled areas under your roof gables, but again a lot of this is personal. 

As a GC I can advise try to retain control of your finishing material orders (anything where you need to make a choice ((tile, flooring, lites, faucets, tubs)) vs. construction materials (2x4s, mortar, shingles)) because we get those discounts on the finishing items and we keep them!

Oftentimes, mobile homeowners will roof their home with a shingle or steel roof for added visual appeal and water protection.

You go metal right over the shingles.  

Hiring a bookkeeper to watch the income/expenses is like hiring a gardener to tell you how many roof shingles are laying on the ground after a wind storm instead of hiring a roofer to repair the roof.I recommend that you look for a quality property manager who can maintain the properties and help with the bookkeeping.Start by going to www.narpm.org to search their directory of managers.

I sold a beachfront home last year that was ICF constructed in 2000 with a metal roof on concrete pilings and the insurance went up triple what my larger 2019 stick built with shingle roof 6 lots down is. 

BUT, the shingle manufacturer requires a nailable surface, which a rotted wood board is not, so they are required to pay for it under that.

About a month ago I had a contractor replace a roof that got damaged from a storm but when they had the shingles off another storm blew through overnight and blew the tarp off and a lot of water got in the house.

I redid the roof… it’s multicolored… used up shingles I had laying around… but still a new roof.Trying to decide if I should sell it.