I can't get on a roof anymore because my knees, feet and ankles have finally said "enough". I was 61 when I did my last roof, I could still nail off four (4) square an hour, notice I said nail off. Depending on the projected temperature for the day I would run my starters and rakes, then lay out ahead of me what I figured I could do before 11:am, we're usually close to 90 degrees by then in the summer, then nail it off.
Most of the work I did was by myself, I'm to picky for most guys who just want to "blow n' go". I was told several times that I could make more money if I would drop my standards, just couldn't bring myself to do that.
I could still nail off six square or better an hour, but when you add the stock time in there It came out to a comfortable 2 1/2 to three square per hour. Not to shabby for an old guy who enjoyed his work. Most of my best times were on five or six twelve roofs.
Working by myself I learned how to do a lot of things to improve my time on a roof to increase my out put, espiecialy on the steeper roofs. I developed systems that improved safety and performance on steep roofs, the less you have to move around on a steep roof to get your shingles, the less your chances are for getting hurt. Placing your shingles where you need them allows quicker dispersement, only making the moves needed to do your work quickly, safer. The last steep roof I did by myself was a 21/12, that was done eight months after a shoulder replacement that went bad, so I was practically roofing that barn with one arm. It was a 21/12 sides and 7/12 top, it was in the dead of winter, Janurary, two snow storms, but nice afternoon temps allowed me to work. I got it done in four weeks, maybe not good time by most of the standards some of you guys on here have, but I thought it was pretty good, the systems I developed helped me out big time.