House Works: Your questions on insulating an attic, winter garages, composite beams

Insulating an old finished attic 
Q: How should I insulate the finished attic in my 1930s house? I just bought the place and the inspector has found evidence of water leaks, probably from ice dams because of insufficient roof insulation. I’m thinking of removing the ceiling, filling the rafter spaces with batts over ventilation channels, then replacing the ceiling. Is my thinking sound?
 
A: It’s common for older homes to have ice damming issues caused by under-insulated ro