I once read that roofing is the most dangerous of all the building trades, except for estimating. When I was learning to build, I made many mistakes –one of them could have been my last. We were just about to start work on the roof of an 1840s farmhouse renovation. I decided I would put up a few roof jacks to make it safer to begin shingling the next day. Everyone else had gone home, and I was alone at the site. The nearest neighbor was _ mile away. I put up a ladder and climbed to the eaves with an armload of jacks. As I stepped onto the roof the ladder shot sideways. I