Ice Dams: What They Are and How to Prevent Water Damage

Every winter across New Hampshire, Massachusetts, and Maine, homeowners face one of the most deceptive threats to their property — the ice dam. What looks like a picturesque row of icicles hanging from your roofline can actually be a sign of serious damage happening right above your head.

At Burke Emergency Restoration, we respond to ice dam water damage calls throughout the winter season. Here is everything you need to know to protect your home.

What Is an Ice Dam?

An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow from draining off. As water backs up behind the dam, it can seep under shingles, into the roof deck, and eventually into your walls, ceilings, and insulation.

The damage is often invisible at first. By the time you notice a water stain on your ceiling or peeling paint on a wall, the water has already been sitting inside your home for days — or weeks.

What Causes Ice Dams?

Ice dams form when three conditions exist at the same time:

1. Snow on the roof
2. Heat escaping from the living space below — warming the roof deck and melting the snow
3. Freezing temperatures at the roof's edge — where the overhang is not heated by the interior

The melted snow runs down toward the cold eave, refreezes, and builds up into a dam. More meltwater pools behind it, and that standing water finds any crack, gap, or imperfection in your roofing to work its way inside.

Homes with poor attic insulation and inadequate ventilation are most vulnerable. But even well-insulated homes can develop ice dams during extreme New England winters.

Signs You Have an Ice Dam Problem

Watch for these warning signs:

• Large icicles hanging from your gutters or eaves — especially if they are thick and continuous
• Ice buildup at the roof edge that extends up onto the roof surface
• Water stains on interior ceilings or walls, particularly near exterior walls
• Peeling paint or bubbling drywall on upper-floor ceilings
• Damp or wet insulation in the attic
• Mold or mildew odor in upper rooms — a sign moisture has been present for some time

How to Remove an Ice Dam Safely

Ice dam removal is not a DIY job for most homeowners. Working on a snow-covered, icy roof is extremely dangerous, and improper removal techniques can damage your shingles, gutters, and roof deck.

What Professionals Do

Certified ice dam removal professionals use low-pressure steam to melt through the ice dam without damaging roofing materials. Steam is the safest and most effective method — it melts ice quickly without the impact damage caused by chipping or the chemical damage caused by de-icing salts.

What NOT to Do

• Do not chip or hack at the ice with an axe, ice pick, or shovel — this almost always damages shingles and can create holes in the roof
• Do not use rock salt or calcium chloride directly on the roof — these chemicals corrode metal gutters and flashings and can kill landscaping below
• Do not use a pressure washer — the force will strip granules from shingles and force water deeper into the roof assembly
• Do not climb on an icy roof without proper safety equipment and training

Temporary Relief: The Calcium Chloride Sock Trick

If you cannot get a professional out immediately, a temporary measure is to fill a nylon stocking or tube sock with calcium chloride ice melt and lay it perpendicular across the ice dam, extending over the roof edge. This creates a channel for water to drain through. This is a stopgap — not a solution — and should be followed up with professional removal.

What Happens If Water Gets Inside?

If an ice dam has already allowed water to penetrate your home, you need to act quickly. Water damage from ice dams can cause:

• Saturated insulation — which loses its R-value and can take weeks to dry on its own
• Damaged drywall and plaster — which can crumble, stain, and become a mold substrate
• Rotted roof sheathing and rafters — structural damage that is expensive to repair
• Mold growth — which can begin within 24 to 48 hours of water intrusion and spread rapidly in cold, damp attic spaces

If you discover water intrusion from an ice dam, call a professional restoration company immediately. The longer saturated materials sit, the greater the damage — and the higher the remediation cost.

How to Prevent Ice Dams

The long-term solution to ice dams is addressing the root cause: heat loss from the living space into the attic.

Improve Attic Insulation

Adding insulation to your attic floor keeps heat where it belongs — inside your home — rather than warming the roof deck above. The recommended insulation level for New Hampshire attics is R-49 to R-60.

Improve Attic Ventilation

Proper attic ventilation keeps the roof deck cold and uniform in temperature, preventing the freeze-thaw cycle that creates ice dams. Soffit vents, ridge vents, and baffles work together to move cold outside air through the attic space.

Seal Air Leaks

Even with good insulation, air leaks around recessed lights, attic hatches, plumbing penetrations, and chimneys can allow warm air to escape directly into the attic. Sealing these bypasses is one of the most cost-effective steps you can take.

Install Ice and Water Shield

During a roof replacement, ask your contractor to install ice and water shield membrane along the eaves — typically the first three to six feet of the roof. This self-adhering membrane creates a watertight barrier even if water backs up under the shingles.

Keep Gutters Clear

Clean gutters in late fall allow meltwater to drain freely rather than pooling and refreezing at the roof edge.

When to Call Burke Emergency Restoration

If you have discovered water damage from an ice dam — wet ceilings, stained walls, damp insulation, or visible mold — do not wait for spring to address it. Water damage worsens over time, and mold can establish itself quickly in cold, damp conditions.

Burke Emergency Restoration provides 24/7 emergency water damage response throughout Southern New Hampshire, Northern Massachusetts, and Southern Maine. Our team will extract water, dry structural materials with industrial equipment, and restore your home to pre-loss condition.

Call us any time: (855) 716-2875.

We have been helping New England homeowners recover from winter water damage for over 20 years. When ice dams strike, we are ready.