I'm in snowy Minneapolis, living in a 3-story house built in 1886. The top floor is fully-finished and heated, and there's no attic.
We've been getting crazy ice dams this year, but not previous years. The ice dams form right where the 2nd and 3rd floor meet. Fortunately I haven't noticed any leaks yet. But I'm worried, and don't know what to do since all the floors are heated.
1/3: This is taken from a 2nd story window.
2/3: Here's the outside. Apologies it doesn't show the whole roof.
3/3: This old real estate listing photo is taken from inside the top/3rd floor. The center-left window below is the top-center window above.
Since the floors are all heated, how can I prevent ice dams? Thank you!