Ice Dams, Icicles and Gutters in Kansas

How ice dams form

An ice dam is a ridge of ice at the roof edge that holds back melting snow. The sequence goes like this: snow covers the roof; heat from the house warms the roof deck above the living space; snow there melts and the water runs down; when it reaches the overhang, which is outside the heated area and colder, it refreezes. Day after day the ridge grows, and water ponds behind it. That water can work back under shingles and into the attic, walls and ceilings.

Kansas winters and ice

Wichita averages about 12.7 inches of snow a year, with measurable snow on about nine days, and the average window for freezing temperatures runs from about October 25 to April 9 (Wikipedia: Wichita, Kansas (climate)). That is modest compared with the upper Midwest, so ice dams here are less frequent. They still happen in snowy stretches, and freezing rain events can coat gutters, roofs and trees in ice. The National Weather Service Wichita office issues winter storm and ice warnings for the area (National Weather Service Wichita forecast office).

What gutters have to do with it

• Gutters do not cause ice dams on their own. The cause is heat loss into the roof.
• Clogged gutters make things worse. Leaves and water frozen in a gutter give ice a starting point at the eave, and the extra weight pulls hangers loose.
• Ice is heavy. Gutters packed with ice can sag or tear off, especially on old spikes or rotted fascia.
• Big icicles along gutters are a sign of melting and refreezing at the eave, and a falling hazard over doors and walks.

Fixing the cause: insulation and ventilation

1. Air sealing. Warm air leaks into the attic through gaps around light fixtures, bath fans, attic hatches, plumbing and wiring. Sealing those is often the most effective single step.
2. Insulation. Enough attic insulation keeps heat in the living space and the roof deck cold.
3. Ventilation. Soffit vents let cold outside air in at the eaves and ridge or roof vents let it out, keeping the roof deck closer to outdoor temperature. Insulation should not block soffit vents. See fascia and soffit.
4. Bath and kitchen fans should vent outdoors, not into the attic.

What helps at the gutter

• Clean gutters before winter. A late-fall cleaning removes the debris ice forms around. See how often to clean gutters.
• Solid hangers. Hidden hangers screwed into solid wood at close spacing hold up better under ice.
• Clear downspouts. A frozen or clogged downspout turns the whole gutter into an ice trough.
• Discharge away from walks so meltwater does not refreeze where people step.

Heat cable

Electric heat cable (heat tape) installed in a zigzag along the roof edge and through gutters and downspouts can keep channels open for meltwater. It treats the symptom rather than the cause, uses electricity, and must be installed according to the manufacturer's instructions with appropriate electrical protection. It can make sense for a trouble spot, such as a north-facing eave over an entry, while insulation and ventilation are addressed.

Gutter guards and ice

Some guards hold snow and ice on top of the gutter, and some are designed to work with heat cable. Guards do not cause ice dams, but if you live with frequent ice at a particular eave, ask how a given guard behaves in snow and ice. See gutter guards.

Removing ice safely

• Do not climb a ladder onto an icy roof or lean a ladder against ice-loaded gutters.
• Do not chip ice with hammers, picks or shovels, which damage shingles and gutters.
• A roof rake used from the ground can pull snow off the lower few feet of roof, reducing meltwater.
• Calcium chloride ice melt in a stocking laid across the dam can open a channel. Avoid rock salt, which can harm plants and metal.
• Knock down dangerous icicles over walkways from a safe distance, or block off the area.

Ladder work in winter is especially risky. CDC NIOSH reports more than 500,000 people treated and about 300 deaths a year in the U.S. from ladder-related injuries (CDC NIOSH, National Ladder Safety Month).

After the thaw

Check gutters for sagging, loosened hangers, separated corners and dents. Look at the fascia and soffit for staining, and inside for ceiling or wall stains near exterior walls. Repairs are covered under gutter repair.

Signs of ice dam trouble inside

Water stains on ceilings near exterior walls, damp insulation, frost on the underside of the roof deck in the attic, and peeling paint near the top of exterior walls can all be signs that water or warm moist air is reaching places it should not. Checking the attic with a flashlight on a cold day can reveal frost, gaps and blocked vents.

Related services

• Gutter Cleaning: Clear leaves, seeds, shingle grit and clogs from gutters and downspouts, then flush and check them.
• Fascia & Soffit Behind Gutters: Repair or replace rotted fascia and damaged soffit so gutters have something solid to hang on.
• Gutter Guards & Covers: Screens, micro-mesh and covers that keep leaves and seeds out of gutters and cut down on cleanings.

Sources: Wikipedia: Wichita, Kansas (climate); National Weather Service Wichita forecast office; CDC NIOSH, National Ladder Safety Month.