Ice Dams: The Hidden Damage They Cause to Roofs and Gutters

1. Heat escapes from your attic into the roof

2. Snow melts on warmer upper roof areas

3. Meltwater flows downward

4. Water refreezes at the colder roof edge

5. Ice builds up, creating a ridge (the “dam”)

As more snow melts, water gets trapped behind the ice barrier—with nowhere to go.

Why Ice Dams Are So Common in the Midwest

Wisconsin and Illinois winters create ideal conditions for ice dams:

• Heavy snowfall

• Fluctuating temperatures around freezing

• Sun exposure during the day and freezing at night

• Poor attic insulation or ventilation

Repeated freeze–thaw cycles worsen the buildup.

Hidden Roof Damage Caused by Ice Dams

Ice dams don’t just sit on top of your roof—they force water underneath your roofing materials.

1. Water Backing Up Under Shingles

When water can’t drain off the roof, it backs up beneath shingles.

This can lead to:

• Wet roof decking

• Interior ceiling leaks

• Stained drywall

• Peeling paint

Even small amounts of trapped water can cause significant long-term damage.

2. Roof Deck Rot

Repeated winter seasons with ice dams allow moisture to soak into roof decking.

Over time, this may cause:

• Soft or sagging roof areas

• Structural wood rot

• Compromised support beneath shingles

Rot often remains hidden until significant deterioration occurs.

3. Damaged Underlayment

Roofing underlayment is designed to provide a secondary moisture barrier. However, constant exposure to trapped water weakens this layer, reducing its effectiveness during future storms.

Gutter Damage from Ice Dams

Ice dams don’t only damage the roof—they place enormous stress on gutters.

1. Heavy Ice Weight

Ice accumulation along the roof edge often extends into the gutters.

This added weight can cause:

• Gutters pulling away from fascia boards

• Bent or warped sections

• Separated seams

Midwest winters with heavy snow loads make this particularly common.

2. Fascia and Soffit Rot

When gutters sag or overflow due to ice buildup, water can seep behind fascia boards.

This may result in:

• Wood rot

• Mold growth

• Paint deterioration

Once moisture penetrates these areas, repairs can become more extensive.

3. Drainage Failure During Thaw

When temperatures rise, large volumes of water may suddenly melt.

If gutters are clogged with ice, water overflows down siding and near the foundation—potentially causing basement moisture issues.

Interior Damage from Ice Dams

Many homeowners first notice ice dam problems inside the home.

Common signs include:

• Water stains on ceilings

• Wet attic insulation

• Mold or musty smells

• Peeling interior paint

By the time these symptoms appear, water intrusion has often been happening for weeks.

Why Ice Dams Get Worse Each Year

Ice dams are often a recurring issue.

If the underlying causes—such as poor insulation or ventilation—aren’t corrected, each winter adds more stress to the roofing system.

Small vulnerabilities grow larger with every freeze–thaw cycle.

Preventing Ice Dam Damage

While no home is completely immune, several steps greatly reduce risk.

1. Improve Attic Insulation

Proper insulation prevents warm indoor air from escaping into the attic and melting roof snow unevenly.

2. Ensure Balanced Ventilation

Soffit and ridge vents help maintain consistent roof temperatures.

3. Seal Air Leaks

Air gaps around attic hatches, recessed lights, and ductwork allow warm air into the attic.

Sealing these leaks reduces heat buildup.

4. Maintain Gutters

Clean, properly secured gutters allow meltwater to drain effectively during thaw periods.

5. Install Ice and Water Shield

When replacing a roof, adding an ice and water barrier along eaves provides extra protection against water backup.

Warning Signs You Shouldn’t Ignore

Call for an inspection if you notice:

• Large icicles along roof edges

• Repeated winter leaks

• Sagging gutters

• Visible ice buildup along eaves

• Interior ceiling stains during winter

Early action prevents structural damage.

Frequently Asked Questions

Are icicles always a sign of ice dams?

Large or persistent icicles often indicate heat escaping from the attic and potential ice dam formation.

Can ice dams damage new roofs?

Yes. Even new roofs can be damaged if insulation and ventilation are inadequate.

Is removing snow from the roof helpful?

Careful snow removal may reduce buildup, but underlying ventilation issues must still be addressed.

Does homeowners insurance cover ice dam damage?

Coverage depends on policy details and maintenance history.

Do gutter guards prevent ice dams?

They may reduce debris buildup but do not eliminate ice formation caused by heat loss.

Protecting Your Roof Through Midwest Winters

Ice dams may appear harmless at first, but the hidden damage they cause to roofs and gutters can be significant. In Wisconsin and Illinois, proper insulation, ventilation, and drainage are key to preventing long-term winter damage.

Huskie Exteriors works with homeowners across the Midwest, providing roofing and gutter solutions designed to handle harsh winter conditions. Addressing ice dam risks early helps protect your home from leaks, structural damage, and costly repairs season after season.