Ice dams occur after a heavy snowfall when warm air in the attic causes the roof to warm and the snow to melt. Water running down the roof refreezes when it reaches the colder roof edge, forming a mound of ice.
Icicles are a sure sign of poor roof ventilation and poor insulation in your home. Warm moist air from inside your home can move upwards and leak around ceiling lights through poorly insulated ceilings and around attic access openings.
Temp fix for the issue:
Lay the hose onto the roof so it crosses the ice dam and overhangs the gutter. If necessary, use a long-handled garden rake or hoe to push it into position. The calcium chloride will eventually melt through the snow and ice and create a channel for water to flow down into the gutters or off the roof.