The size of these icicles can indicate that the ice dam is progressing significantly. This attic needs an air seal and insulation upgrade.
When the water is forced to drain behind the gutter, it may start to freeze on the siding or the downspout. The ice buildup continues and causes a domino effect of damage!
In this example you can see where the ice dam is causing the water drainage to back up, starting to re-freeze, putting the roof shingles in danger of damage and leaking.
More examples of icicles from ice damming.
Sometimes icicles can grow to become safety hazards. In this case, they can cause slippery stairs or injury if they break and land on a person below.
The iced damming on this house has progressed to the point where the water is draining behind the gutters and forming ice on the side of the house.
When the gutters are blocked by ice dams and cannot drain properly, the water can discharge and collect right by the foundation and can then sometimes find it's way into the basement!
Ice Damming occurs when heated air from the home leaks up into the attic, warms the roof, and melts snow. When the water runs down the roof and reaches the cold eaves and gutters, it re-freezes. This can lead to icicles and a ridge of ice at the eave. The ridge gets thicker as the progression repeats, and blocks the melted snow from flowing off the roof. Water puddles (dams) behind the ice ridge and can push back up underneath the roof shingles, flooding the attic, raining water down inside the house. This can cause a tremendous amount of damage to drywall, cabinets, furniture, finishes, and flooring.