What Causes Icicles on Gutters & Attic Insulation?

Causes

• Roofs seal in heat and prevent water from entering a home. Gutters drain water from rooftops and also help prevent water from entering homes. When gutters are clogged, water collects in valleys and drains. This water freezes during cold weather and forms icicles. Collected water also leaks into attics where it becomes trapped in insulation and freezes.

Damage

• Icicles weigh down drains, and have the potential to tear gutters and downspouts from roof lines and house edges. Trapped water damages insulation and roofing, both exterior and interior, by promoting mold development and causing structural damage through the expansion and retraction of freeze thaw cycles.

Prevention

• Clear gutters of leaves and debris prior to freezing weather and temperatures. Install heat tape along gutters. Heat tape is available at most home improvement and hardware stores. The tape is powered by electricity and must be plugged in so that it will steadily release warmth to the area in which it is applied. Avoid fire hazards by using only certified gutter heat tape and inspect the tape annually for fraying and damage. Heat tape should be replaced every three years. Do not place tape near, over or under insulation. Insulation can catch fire when placed near heat tape, heaters, electrical outlets and light fixtures. Insulation is kept dry when gutters are clear and leaks do not penetrate the roof. Install insulation with a vapor barrier to prevent home humidity and outdoor moisture from entering the insulation.

Considerations

• Poorly ventilated and insulated homes run the risk of creating ice dams on roofs. Since heat rises, a poorly ventilated home will fail to redistribute heated air throughout the house. Instead heat will naturally rise and collect in the attic area. Attics should remain cooler than the rest of the house to prevent the formation of ice dams on the roof top. Snow sitting on a warm roof is more apt to melt. This ice melts quickly but freezes once it is exposed to colder temperatures at roof edges. Here it will form ice dams and icicles and cause damage.