Roof Maintenance for Icicles

Formation

• Icicles are actually the frozen runoff from ice dams, which are blocks of ice that form on and near gutters and roof edges. If your roof is letting heat escape from your attic or crawlspace, that heat will melt snow that’s fallen on that spot. The melted water runs down to the gutter, and once it reaches part of the overhang that isn’t over a heated area, it refreezes. This builds up a small wall of ice that is just big enough to catch further melted water, creating a standing puddle on the roof that occasionally spills over.

Why They’re a Danger

• Icicles are not only a sign that an ice dam has formed on your roof, but they are dangerous in and of themselves. Thawing icicles don’t merely melt away gradually; they also break away from the roof once the sections holding them there become too thawed and weak to hold the weight of the rest of the icicle. Falling icicles can injure and kill you -- this is a solid, pointed object falling toward your head from a height. For example, the BBC reported in 2001 that three people had been killed in Moscow, Russia, by falling icicles after heavy snows and cold temperatures resulted in icicles several meters in length.

Preventive Maintenance

• Inspect the underside of the roof inside your attic regularly for leaks and wet spots, and see if you can identify any cracks in the roof or walls, or any hotspots in the floor that are letting heat from the rest of your house get into the attic. Add more roof insulation if necessary to keep heat in, and consider adding an ice and water barrier under the shingles the next time you have your house re-roofed. Another option is literal electric tape, called “heat tape” or “heat wire,” which you place along the eaves and plug into an outlet. The tape keeps parts of overhanging areas warm so water can’t refreeze.

Mitigation

• If you find icicles hanging off your gutters, identify those areas of the roof that are losing heat by looking for exposed areas with little or no snow. Remove snow on the roof with a specialized snow rake or roof shovel -- stay on the ground to use it and do not get up on a ladder -- and immediately try to cool down your attic or crawlspace to prevent more snow from melting. If you see water leaking into your attic because of the dam aim a fan at the water so that it cools and freezes, thus blocking any more from coming in temporarily. However, to get rid of icicles and ice dams themselves you need to call a professional roofer because of the danger in going up on an icy roof yourself and the damage you could potentially do to the roof.