Icicles on the roof were a highlight of my childhood winters. The neighborhood kids thought they were fantastic for both impromptu swordfights and a refreshing snack. But when you grow up and do adult stuff like owning a home, those icicles kind of lose their appeal. Especially after you find out they’re signaling that your roof might be in trouble. Learn why, and what you can do about it.

How do icicles form?

If you live in a northern state, cold winters and heavy snowfalls re the norm. When the weather clears up and the sun comes out or when the heat inside your home travels to the outside, the snow on your roof will melt – at least partially. As the snowmelt starts to drip off, contact with the sub-zero air freezes it up again, in the form of small frozen droplets. New drips run along the sides of these icicles-in-the-making and then freeze as they move downward, causing the icicles to grow in size -- sometimes spectacularly. The record for the longest icicle is in dispute, but claims range from 28-45 feet.

Dangers of icicles on the roof

While snowy scenes of icicles on a house look beautiful, even cozy, these ice formations are actually dangerous. Large falling icicles, knocked down by wind or loosened by a spell of sunshine, can damage anything in their path with their heavy weight and pointed tips. They’re capable of pulling gutters off your house, shattering windshields of vehicles below, and causing laceration or concussion – or worse! -- to any human who happens to be standing near the roof eaves.

Ice dams

Where there are icicles on your roof, there are often ice dams as well. More bad news! What is an ice dam on a roof? It’s a ridge, or dam, of ice that builds up along the lower edge of the roof, blocking snowmelt farther up from running harmlessly toward your gutters or the ground. Instead, the liquid soaks into your roof and attic, resulting in potentially serious water damage. The cause of ice dams and icicles is similar -- snow on the roof is warmed enough to melt, and then refrozen into ice formations.

HEADS UP: While the presence of an ice dam may be signaled by icicles on your roof, it’s possible to have an ice dam without any icicles to warn you.

What to do

DIY removal of ice formations from your roof is tricky. Follow these tips to make the process easier and safer:

Tap small icicles off your roof before they have a chance to get bigger.

Gently does it when dislodging large icicles. And never stand directly beneath an ice formation -- use a wooden stick to extend your reach.

Be careful if you need to use a ladder. Don’t prop it on an icy roof or gutter. And, for heaven’s sake, don’t try walking around on your ice- or snow-covered roof.

Remove snow from your roof with a long-handled plastic shovel or snow rake. Plan ahead where you want the load of snow to fall.

Avoid using ice melt products on your roof. They can destroy your shingles. Ditto for crude ice-breaking tools like hatchets or ice picks.

Form channels in an ice dam to facilitate water drainage; spray lines of warm water with your garden hose, from the roof eaves upward.

Play it safe and hire a roofing professional to deal with major icicles and ice dams. Pros have the know-how, as well as specialized steam machines, to safely get ice and snow off your roof.

Prevention of ice dams and icicles on your roof.

The best prevention is to: A) to clear your gutters every fall, so water can drain off readily and B) cool down your roof – insulate and seal the attic, and install roof and soffit vents.


Backup solutions include:

Rake the snow off your roof regularly. Don’t worry about every last flake; just keep it reasonably clear.

Add an adhesive ice-and-water barrier when you next replace your roof. Consider making that new roof a metal one, the easiest type for snow to slide off.

Install heating cables on the roof edge, as a last resort.

Laura Firszt writes for networx.com.