My dad used to be my brother's handyman for his rental properties in exchange for free housing. I spent one winter helping him out on weekends. Learned a lot of useful things, many of them in the "what not to do" category. We had a lot of snow that winter and we spent a lot of time up on various roofs removing snow and ice. I have yet to forget the sight of my dad, half-way up the ladder when it slid away from the house. He had this resigned look on his face and if he had been a famous cartoon coyote, would have been holding up a sign that said "Oh, shit!" I did check the ladder to see if it had "Acme" anywhere on it.