Frozen gutters in Sioux Falls are a sign of an ice dam, not a gutter problem. Heat escaping into the attic melts snow on the upper roof, and the water runs down to the cold roof edge and refreezes in the gutter and along the eave. The lasting fix is in the attic: seal the air leaks in the ceiling, then add insulation. Roof raking, clear downspouts and, in a few cases, heat cable manage the ice until then.
How do ice dams form?
An ice dam needs snow on the roof, an upper roof surface above 32 degrees and a roof edge below freezing. Snow melts where the roof is warm, and the water freezes when it reaches the cold eave. The ridge of ice grows with each melt, and water pools behind it. That water finds gaps between shingles and can leak into the attic, the walls and the ceilings below. Plenty of gutter leaks have nothing to do with ice.
The heat comes from the house. In many homes the biggest source is warm air leaking into the attic through light fixtures and other openings in the ceiling. Bathroom and kitchen fans that vent just above the roof, chimneys and ductwork in the attic add to it.
Signs of an ice dam
- A ridge of ice along the roof edge
- Icicles hanging from the gutters or the eave
- Gutters packed with ice
- Water stains on ceilings or walls near the outside walls
How do you get rid of an ice dam safely?
The safest way to deal with an ice dam is from the ground, and the rest is a job for a pro.
- Rake the snow. After a heavy snow, pull snow off the lower few feet of the roof with a roof rake while standing on the ground. It removes the snow that feeds the dam, though the rake can scuff shingles.
- Make a channel if water is coming in. On a mild day, run tap water from a garden hose over the dam, working upward from its lower edge. The channel lets trapped water drain, but it only lasts a few days.
- Hire steam removal for a large dam or an active leak. Ice dam removal services use low-pressure steam that melts the ice without damaging the roof.
- Don’t chip, chop or use heat or chemicals on the roof. They damage shingles and gutters.
- Stay off the roof. Winter roof work is dangerous, and a fall from an icy ladder is the biggest risk in the whole job.
If water has come inside, dry the ceilings and walls completely before any repairs, or mold can follow.
Does heat cable prevent ice dams?
No. Heat cable melts a path for water through the ice at the roof edge and in the gutter, but it does nothing about the heat loss that causes the dam. It also shortens the life of the roof and adds to the power bill.
What it costs to run depends on length and hours. A common roof and gutter cable draws about 5 watts per foot, so a 100-foot run draws 500 watts. Left on around the clock from December through February, that comes to about 1,080 kilowatt-hours, or roughly $150 at South Dakota’s average residential rate of about 14 cents per kilowatt-hour. A thermostat or moisture control cuts that down.
Heat cable fixed to a roof or gutter needs ground-fault equipment protection under the National Electrical Code. That device trips at a different level than a standard GFCI outlet, so the circuit should be set up by an electrician. Use cable made for roof and gutter deicing, and install it to the maker’s instructions.
Heated gutters and gutter ice melt systems are the same idea: heat cable run inside the gutter and downspout, sometimes built into a gutter guard. They carry the same trade-offs.
Heat cable makes sense for a spot that still ices after the attic has been sealed and insulated, not as the first fix. Metal roofs add sliding snow to the picture.
Why do downspouts freeze?
Downspouts freeze when meltwater reaches cold metal faster than it can drain. A downspout half-blocked with leaves freezes solid first, so clean the gutters and downspouts in the fall before the first hard freeze. Once the snow is off the roof in spring, walk around and check the gutters for what the winter pulled loose.
Buried downspout lines freeze because they sit well above the frost line. An overflow tee near the downspout lets water out above ground when the line is frozen. Our downspouts and drainage guide shows how to set one up.
Watch where the water lands. An extension that sends meltwater across a sidewalk or driveway builds a sheet of ice. Sioux Falls requires property owners to clear snow and ice from sidewalks within 48 hours, and sump pump water may not ice a street, alley or sidewalk. Point extensions toward the lawn.
What Sioux Falls requires at the roof edge
Sioux Falls requires an ice barrier on shingle roofs. The city’s building code marks it as required, and the national model code reserves that for places with a history of ice-dam damage. The barrier is a waterproof layer under the shingles that runs from the roof edge to at least 24 inches inside the exterior wall line.
An ice barrier does not stop ice dams from forming. It keeps the water that backs up behind one from reaching the roof deck. A new or replacement shingle roof in Sioux Falls should include one, so ask for it in any roofing quote.
Should gutter guards come off for winter?
Gutter guards do not need to come off for winter. A guard lying flat across the gutter can hold a ridge of ice along the edge, so a guard installed with a slight pitch sheds snow and meltwater better. Each guard type behaves differently under snow.
How to prevent ice dams for good
Ice dams stop when the roof stays cold. Seal the air leaks between the house and the attic first: around light fixtures, fans and other openings in the ceiling. Then add insulation. Move bathroom or kitchen exhausts that end just above the roof so they vent well away from it. Powered attic fans are not recommended, because they can pull warm air out of the house and cause moisture problems.
A weatherization contractor can find the leaks with a blower door test and an infrared camera, which show where heat is escaping through the ceiling.
Questions about frozen gutters and ice dams
Why are my gutters frozen?
Heat escaping into the attic melts snow on the roof, and the water refreezes at the cold roof edge and in the gutter. Clogged gutters and downspouts freeze faster.
Does heat cable prevent ice dams?
No. It keeps a path open for meltwater but does not fix the attic heat loss that causes the dam. Sealing air leaks and adding insulation prevent ice dams.
How much does it cost to run gutter heat cable?
A 100-foot run at 5 watts per foot costs roughly $150 to run nonstop from December through February at South Dakota’s average electric rate. A thermostat or moisture control lowers that.
Should I remove ice from my gutters?
Don’t chip it out. Chipping can crack shingles and bend or pull the gutter loose. Rake snow off the lower roof, keep downspouts clear, and hire steam removal for a large dam or an active leak.
Do I need to remove gutter guards in winter?
No. Leave them on. A guard lying flat can hold ice at the edge, so a slight pitch works better.
Get a quote
If ice dams keep forming or your gutters are sagging from the weight of ice, tell us about the job with a photo, and a local gutter contractor will call, text or email to set up a visit. The quote is free.