Can Insulating a Gutter Spout Stop It From Freeezing?

Ice Dams

• A poorly insulated attic and heat leaks from the living area can keep parts of the roof warm enough to melt the bottom of any accumulated snow. When the ice water reaches the exposed part of the roof, the water freezes again. Ice dams often form on the edge of the roof, but ice also can build up in gutter troughs. Ice dams can form from only two inches of snowfall, but the worst problems occur when extreme cold follows heavy snow, according to the University of Massachusetts at Amherst. Keeping downspouts open won't prevent ice dam problems.

Insulation

• If you heat the gutters, a layer of insulation around the downspout saves energy. Running waterproof outdoor heat tapes along gutter troughs and down the sides of downspouts keeps the entire system ice-free in mild winter weather. Insulating the downspouts keeps that part of the system warm at less cost, but without the heat tape, the insulation does little good. Flowing water helps keep protected pipes open, but trickles of water quickly build up layers of ice in exposed downspouts. Heat tapes won't keep a gutter system working in severe cold.

Maintenance

• Cleaning the gutters before the first winter storm hits gives the system the best chance of correctly working. Gutters that aren't properly aligned cause water to back up in the trough; in the winter, any water that doesn't move through the system quickly freezes. Leaves and twigs in the trough also cause small backups that turn into ice clogs. During the fall rains, inspect the system to make sure all the downspouts properly work. Birds and rodents sometimes build nests in downspouts, and unless screens keep debris out, clogs form at the bends. Don't try to solve gutter problems in icy conditions.

Protection

• A working gutter system during winter storms can prevent ice water from backing up under roofing and into the attic. Heat tapes also protect the gutters themselves from collapsing under the weight of snow and ice. To keep the gutters from freezing requires 2 feet of heating cable running from 5 to 7 Watts for every 1 foot of gutters, according to the University of Missouri. Heat cables must lie parallel in the gutters, since any crossovers could overheat and short out the system. Insulating a heated downspout can cut energy consumption by about 75 percent, but only if the insulation stays dry.