I’d like to raise a few points to the discussion of ice dams and snow removal;
1) Poor insulation in walls and in attics is a major cause of ice dams. While ice dams will occur just from solar melting, heat from your attic and exterior walls is a major cause of the ice melting and freezing which create a back flow and leaking. If you have significant leaking or dams you should look into adding or improving your insulation this spring or summer. Read this article that I wrote and there’s plenty more all over the web.
2) You should check to see if the people who are climbing all over your roofs hacking at the ice have liability insurance and most importantly workman’s comp insurance. f they don’t have workers comp, and they fall, they can make a claim against the homeowner for injury and heath benefits. Ask them to show you their certificates or insurance binders.
3) Anyone who is on your roof needs to be roped in and in a harness. A ladder must extend 3′ above the gutter if anyone is transitioning from the ladder to the roof. Obviously it’s the safe way to go. If you need more persuasion, the OSHA fine for not being roped in is upwards of $7000. If you hire someone to go up on you’re roof (other than a “real company”), you will be responsible for the fine (you’re the employer). This sounds nuts, but go argue it with OSHA for a while.
Stay safe and stay warm!