Guide · Roof & Gutters
Ice dams look dramatic — that thick ridge of ice along the eaves, the icicles hanging off the gutter — but the cause is quieter than it looks, and it is worth understanding before you spend money on the wrong fix. Here is what an ice dam actually is, where it really comes from, and the honest truth about where clean gutters fit in.
An ice dam is a ridge of ice that forms at the edge of a roof and stops melting snow from draining off. It happens when the roof has an uneven surface temperature: the upper part of the roof is warm enough to melt snow, while the eave and overhang at the bottom stay below freezing. Snow melts up high, the water trickles down, and when it reaches the cold edge it freezes again. Do that over a few cold days and a wall of ice builds up along the eave.
The problem is not the ice itself — it is the water it traps. Once the dam is there, the next round of meltwater pools behind it and stays liquid, and liquid water finds every seam and nail hole in the roof. From there it can work its way under the shingles and into the attic, and sometimes down into walls and ceilings. That is the part that causes the damage people remember.
Here is the part a lot of quick-fix advice skips over, so we will say it plainly: ice dams are caused by heat escaping from your house into the attic. The upper roof only melts snow because warmth from inside the home is leaking up through the ceiling and warming the roof deck from below. The University of Minnesota Extension, which has studied this for decades in a climate a lot like ours, is blunt about it — for an ice dam to form, higher parts of the roof surface have to sit above freezing while the eaves stay below it, and that heat almost always comes from the house.
That heat gets up there three ways: warm air leaking through gaps around light fixtures, hatches, and pipes; heat conducting straight through thin or missing insulation; and, in some homes, poorly sealed ductwork or chimneys sitting in the attic. Air leakage is often the single biggest culprit. So the durable fix is the unglamorous one — seal the ceiling so warm air stops leaking up, add insulation to slow the heat that conducts through, and ventilate the attic so any stray heat is carried away and the roof deck stays uniformly cold.
We will be honest about our lane here: that insulation, air-sealing, and ventilation work is not something Nord does. We are an exterior cleaning company, not an insulation or roofing contractor. If your home dams up badly every winter, the real answer is inside the attic, and the right person to call is a weatherization or roofing contractor who can check how airtight your ceiling is and put the insulation and ventilation right. We would rather point you there than sell you something that treats the symptom.
This is the honest bit, and it cuts both ways. Gutters do not cause ice dams. A house with no gutters at all can still form them, because the cause is the warm roof above, not the trough below. If anyone tells you your gutters are the reason you get ice dams, they have the mechanism backwards.
But clean gutters genuinely help, and clogged ones genuinely hurt. When your eavestrough and downspouts are clear, meltwater that does run down the roof has somewhere to go — it drains away instead of pooling at the edge. When the trough is packed with leaves and pine needles, that meltwater has nowhere to drain. It sits in the trough, freezes into a solid block right at the coldest part of the roof, and adds both weight and a ready-made foundation for the dam to grow on. A clogged gutter does not start an ice dam, but it makes an existing one heavier, wider, and slower to let go.
That is why the fall gutter clear is real prevention rather than a cash grab — done after leaf-fall and before the freeze, it means your drainage is working the moment the first thaw comes, instead of holding ice at the eave all winter. It will not cure a heat-loss problem, and we will not claim it does. But it is a genuinely worthwhile, low-cost thing to have crossed off before winter, and it happens to be squarely in what we actually do.
Prevention comes in two layers — the permanent one and the seasonal one. Both matter, and skipping the first is why some homes never seem to get ahead of the problem.
If a dam has already formed, the instinct is to get up there and deal with it. Please do not. Two rules keep you and your roof out of trouble:
Never climb an icy roof. It is one of the most dangerous things a homeowner can attempt in winter, and no ice dam is worth a fall. Anyone working on a snowy or icy roof risks serious injury.
Never chip, hammer, or pry at the ice. It feels productive, but you cannot separate the ice from the shingle without taking granules — and often the shingle itself — with it. You trade a water problem you can fix for a roof problem you cannot.
What is safe: a long-handled roof rake used from the ground, gently pulling snow back from the eave so the dam loses its supply. Be careful with the shingles even then, and never rake near power lines. Be cautious with de-icers too — rock salt thrown straight onto shingles can damage them and stain the surfaces below. And if water is already getting into the house, that is the moment to call a professional who can steam the dam out. Steam melts the ice without the heat or force that harms a roof, and it is the method the pros use for exactly this reason.
Here is exactly what we can and cannot do for you. We clear and flush gutters and downspouts so your drainage works going into winter, and we soft wash and treat roofs — including clearing snow-trapping moss before the cold sets in (that is covered in our roof cleaning guide). Both are honest prevention that make winter easier on your roof edge.
What we do not do is attic insulation, air-sealing, or ventilation — and those are the things that actually stop ice dams from forming. If that is your real issue, we will happily tell you so and point you toward a roofing or insulation contractor rather than sell you a clean that treats the wrong end of the problem. That is the deal we make with every customer: we stay in our lane and tell you the truth about where the fix really lives.
Heat escaping into the attic warms the roof and melts the snow on it. That meltwater runs down to the cold eave, refreezes into a ridge of ice, and that ridge backs the next round of water up under the shingles — where it can leak inside.
No — the cause is attic heat loss, not gutters. But a clogged gutter makes things worse by holding a block of ice at the roof's edge instead of draining meltwater away. Clean gutters help; blocked ones hurt.
Long term, keep the roof deck cold: air-seal the ceiling, add insulation, and ventilate the attic (contractor work). Seasonally, clear gutters and downspouts in fall and keep the roof edge clear of snow with a rake from the ground.
Do not climb an icy roof and do not chip at the ice. Use a roof rake from the ground to pull snow back from the eave, keep rock salt off the shingles, and call a pro to steam out any dam that is already letting water in.
It does not fix the heat-loss cause, so it is not a cure. But a clear, flushed gutter and downspout system drains meltwater instead of holding a frozen block at the eave — worthwhile, honest prevention that is worth doing on its own.
Sources: University of Minnesota Extension, “Dealing with and preventing ice dams” · This Old House, “How To Get Rid of Ice Dams: Prevention & Fast Fixes.”