An ice dam is a ridge of ice along the eaves, and the ridge itself is not what does the damage. The water pooled behind it does. Shingles shed water running downhill, but they do nothing against water standing on them, so meltwater trapped behind the ice backs up under the lower courses and finds its way into the wall and ceiling. In Eau Claire, the ceiling stain near an outside wall that shows up in February is almost always an ice dam.
Two things you should know before you go any further. First, we don’t remove ice dams. Steaming the ice off is done by dedicated ice dam and snow removal outfits with commercial steamers, and if the ice needs to come off today, they are your call. Second, removing the dam only treats the symptom. Heat from the house built it, and it will build again with the next snow unless something changes. Our part is everything after the ice is gone: repairing the roof where the dam did damage, and fixing the roof venting that is part of keeping it from coming back.
Why ice dams form on Eau Claire roofs
The University of Minnesota Extension gives the recipe: snow on the roof, the upper roof surface above 32°F, and the lower edge below 32°F. Snow melts high on the roof, the water runs down to the cold overhang, and it refreezes there, one layer at a time. Eau Claire averages about 55 inches of snow a year, so we have plenty of the first ingredient.
The heat comes mainly from the house. Extension says that in many homes the major source is warm air leaking through ceiling penetrations like light fixtures, and that chimneys, ductwork running through the attic, knee walls, and bath or kitchen exhausts ending just above the roof add more. That explains why some Eau Claire houses dam up every winter while the neighbor’s roof stays clean:
- Story-and-a-half houses, including many of the pre-WWII frame homes in the Third Ward and Randall Park, have heated rooms tucked under sloped ceilings and behind knee walls. The roof sits right on top of living space, with little room for insulation and lots of hidden air paths.
- Mid-century ranches on the North Side often have soffits buried under attic insulation, so the eaves get no cold intake air and the whole underside of the roof runs warm.
The Eau Claire weather page covers how our freeze-thaw winters work on a roof more broadly.
How ice dams on a roof get removed safely
The safe way to remove an ice dam is steam. A commercial ice dam steamer puts out low-pressure steam, HomeGuide puts it at about 290°F, and the operator uses it to cut through the ice down to the shingles and loosen it in blocks without hitting the roof. Because the pressure is low, it melts the ice without blasting the shingle surface. The aim is to open the eaves so the water behind the dam can drain, not to strip every bit of snow off the roof.
Any removal means working on a roof in winter, and the University of Minnesota Extension is blunt that anyone on the roof in winter risks injury, so leave it to professionals. When you call an outfit, ask two things: do they use a true low-pressure steamer, and are they insured for roof work.
Ice dam steamer vs chipping vs pressure washer
Not every company that advertises ice dam removal uses a steamer. The costs below are HomeGuide’s national figures; Eau Claire prices may differ.
| Method | How it works | Cost (HomeGuide, national) | Risk to the roof |
|---|---|---|---|
| Steamer | Low-pressure steam melts through the ice | $800 to $2,400 total; $400 to $600 an hour, 2 to 4 hours | Lowest, when a true steamer is used |
| Chipping | Hatchets, picks, or mallets break the ice up | $800 to $1,800; $200 to $300 an hour, 4 to 6 hours | Cold shingles are brittle and crack or tear under the blows |
| Pressure washer | High-pressure water cuts the ice | $400 to $2,000 | Can strip granules and force water under the shingles |
| Ice melt salt or tablets | Chemical melts a channel | $200 to $300, for minor ice | Rock salt harms shingles, metal, and plants |
| Snow raking | Pulls snow off the lower roof | $200 to $500 per visit | Doesn’t touch the dam; can damage roofing |
The steamer costs more per hour and finishes faster. Chipping can look cheaper until you count the shingles it breaks. A pressure washer with a trigger running at high pressure is not a steamer, whatever the ad says.
Ice dam removal cost, and who pays for it
By HomeGuide’s national numbers, steam removal runs $800 to $2,400. The final bill depends on how much ice there is, how high and steep the roof is, and how many hours the job takes. Minor ice that only needs a channel through it can be handled with melt tablets for a few hundred dollars.
On insurance, HomeGuide notes that policies usually don’t pay for removal itself because it isn’t a covered peril, but they may cover the damage the dam caused, and sometimes the removal of the part of the dam that’s causing the leak. If water got in, photograph it before cleanup and read the storm damage page for how an ice dam damage claim moves forward.
What you can do about an ice dam while you wait
If the removal outfit is booked out, a few things are safe to do from the ground:
- Melt a channel with calcium chloride. Fill a tube sock or stocking with calcium chloride and lay it across the dam, running up and down the roof, so it melts a drain path through the ice. Use calcium chloride, not rock salt.
- Hose a channel on a warm day. The University of Minnesota Extension says tap water from a hose on a warm day works, starting at the lower edge of the dam and working upward. Like any channel, it’s temporary, and Extension notes it stops working within days.
- Rake the lower roof carefully. A roof rake takes away snow before it can melt, but Extension warns it can damage roofing. Pull gently and don’t scrape down into the shingles.
- Stay off the roof and leave the hatchet in the garage. Chipping at cold shingles does more damage than the dam does.
Inside, catch the drips, move what you can, and photograph the stains. If water is coming in faster than buckets can handle, see emergency roof repair.
After the ice dam is gone: checking the roof for damage
This is where we come in. When the eaves are clear, the roof under the dam needs a look, because the damage often doesn’t show from the ground:
- Shingles at the eaves. Ice and any chipping can lift, crack, or tear the lower courses. One or two damaged shingles is a $300 to $750 repair.
- Decking. Water that backed up under the shingles soaks the roof boards along the edge. Soft or stained decking has to be cut out and replaced, which the decking replacement guide explains.
- Gutters and fascia. The weight of the ice bends gutters, pulls hangers loose, and lets water into the fascia board behind them.
- Membrane at the eaves. Wisconsin’s dwelling code, SPS 321.28(4), requires ice barrier membrane on shingle roofs pitched 4:12 or flatter, running at least 30 inches up from the edge and 12 inches past the inside face of the exterior wall. On an older roof, check whether there is membrane at all and whether it reaches past the wall line.
On our roof repair page, roof-side ice dam damage (deck inspection, membrane, and re-flashing) runs $800 to $5,000. Once the interior drywall and insulation are involved, it runs $2,000 to $6,500. If you aren’t sure where the water got in, the roof leak repair guide covers how an entry point gets traced, and a roof inspection in spring catches what winter hid.
Hold off on the ceiling. The University of Minnesota Extension advises against repairing interior damage until the ceilings and walls are dry, and says to do the repair together with fixing the heat loss, or the same stain comes back next winter.
After removal: fixing the attic heat behind the dam
Since the dam is a heat problem, the fix order runs from the house outward:
- Air seal the attic floor. Extension’s first step is making the ceiling airtight: light fixtures, plumbing and wiring holes, the attic hatch, chimney chases, and knee walls. Insulation and weatherization contractors usually do this work, and Focus on Energy’s Trade Ally locator is a good place to find one.
- Add insulation. Extension’s order is insulation after air sealing, because insulation does little against air leaking straight through it.
- Fix the venting. We handle this part: open soffit intake, baffles that keep insulation off the vents, and ridge exhaust, so cold outside air runs under the roof deck. Extension does not recommend powered attic ventilators for ice dams. The attic ventilation guide has the vent math and explains why a brand-new roof can still get ice dams.
- Heat cables last. They manage the symptom on spots that can’t be fixed any other way.
Ice barrier membrane belongs on every roof that needs it, but it’s a backstop that keeps water out when a dam forms, not the thing that stops dams from forming.