How to Remove an Ice Dam Safely Before It Leaks

How to remove an ice dam: do it from the ground and from inside the house. Pull snow off the lower roof with a roof rake, cool the attic, melt channels with calcium chloride in a stocking laid across the dam, and call a pro for steam if water is already coming in.

Never climb an icy roof or hack at ice with a hammer.

How to remove an ice dam: why they form

An ice dam is a ridge of ice at the roof edge that traps melted snow behind it. Heat leaking from the house warms the upper roof, snow melts, runs down to the cold overhang and refreezes. The pooled water can then back up under shingles and leak into walls and ceilings.

Quick facts: how to remove an ice dam
Safe first step	Pull snow off the lower roof with a long-handled roof rake from the ground
Quick melt channel	Calcium chloride in a tube sock or stocking laid across the dam
Fastest professional method	Low-pressure steam from a trained crew
Never	Chip with an axe or hammer, use a torch or climb an icy roof

Safe ways to deal with it

Method	Notes
Roof rake	Pull snow down from the eaves while standing on the ground; leave a thin layer to protect shingles
Calcium chloride	Fill a stocking and lay it vertically across the dam so it melts a channel; do not use rock salt, which can damage roofing and plants
Box fan in the attic	Blow cold air against the roof deck from inside to refreeze the melt
Steam by a professional	Low-pressure steam removes ice without damaging shingles when done by trained crews
Warm-air leak sealing	Reduces melting from inside after the emergency passes

Step by step

1. Stay off the roof and out from under icicles, which can fall.
2. Use an extendable roof rake from the ground, working along the eaves in short pulls.
3. Fill the legs of old nylon stockings with calcium chloride ice melter, knot them and lay them across the dam so they run from the roof edge uphill.
4. Place them every few feet. As they melt channels, water can drain.
5. Move items away from wet ceilings, and put buckets under drips.
6. Do not poke holes in the ceiling unless a pro tells you to.

What not to do

Do not chip at ice with a hammer or axe, which breaks shingles. Do not use rock salt, which corrodes metal and kills plants. Do not use a pressure washer or a flame. Do not climb a ladder onto icy shingles, especially with snow load. Ladders on ice and wet ground slip easily, so call a professional.

Fix the cause so it does not come back

Ice dams are usually an insulation and ventilation problem. Seal air leaks around hatches, light fixtures and chimneys in the attic floor, add insulation to the recommended level for your area and make sure soffit and ridge vents let cold air flow under the roof deck. A roofer can find the weak points and tell you what to fix first.

If water is already coming in

Move belongings, protect floors, put a bucket under the drip and, if safe, relieve a bulging ceiling by making a small hole so trapped water drains into a bucket. Photograph the damage for insurance and call a professional for steam removal.

When to call a professional

If the dam is big, the roof is steep or high, or water is entering the house, call a roofer or a steam ice-removal crew. Learning how to remove an ice dam helps you act quickly, but safety on icy roofs comes first.

How to remove an ice dam: a safe approach

Removing an ice dam is risky, so approach it with care. Working from the ground with a roof rake is the safest option, pulling snow down from the lower edge so meltwater can drain. Never use metal tools that can damage shingles, and never chop at the ice on the roof. Steam and calcium chloride products are sometimes used, but they can harm roofing and plants, so check the label first. If water is already entering the house, protect the room below and call a roofer for an inspection.

Before you start, learn how to remove an ice dam safely, since the wrong method can cause more damage than the ice. Many roofers only remove ice dams in emergencies, so ask them how to remove an ice dam before winter. The sensible first step in any winter plan is knowing how to remove an ice dam and when to leave it to a professional.

Knowing how to remove an ice dam before the first storm gives you time to plan the safest method.

Related reading

• How to Prevent Ice Dams on Roof Edges: Insulate, Seal, Ventilate
• Does Homeowners Insurance Cover Ice Dam Damage? What to Check
• Water Stain on Ceiling: Find the Source, Dry It and Repair It
• Signs of Poor Attic Ventilation: 10 Clues in Summer and Winter

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