How do I Know if I Have a Warm or Cold Roof?

Good evening,

This is meant for Steve Dickinson.  I find your videos of cold and warm roofs among others excellent.  You make this stuff seem simple.

Few questions:

1) Without knowing anything about my roof, how do I know if cold or warm?  House built in 1920 and previous owners have no clue as to what I am asking.  They only know that it was re flashed 10 years ago, and on flat roofs, not much to re flash so not sure what they are saying.

2) We, like you , are in dead of winter.  We had 10 inches of snow the other night, and I woke up to a leak in back bedroom – not sure but after researching maybe due to what they call ice damming, which then leads me to believe insulation never there or almost not functional.  How do I know without breaking ceilings?  What do you recommend?  Not bother and inquire on warm roof?  That would make sense yes?   A new roof usually comes with all components, insulation etc?

3) How do I avoid these ice damming problems without new roof?  Insulation from within?  They have the expandable version (spray foam I think its called).  Any ideas?

I would appreciate any help!

Thanks