Reed wrote:

As odd as it sounds go up the ladder and attack the ice with a good
load of road salt. It will melt the ice without causing any damage to
your shingles. People have been doing this around here for years.

OK, I'll try some tomorrow. I assume, like a car, it would be good to
rinse everything later with water when possible.

Don't be too generous with the chemistry: salt and brine dripped onto
plants below may damage or kill them. Of course, this is a potential
problem only if the great snows of Denver aren't permanent.