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icicle on the house roof in winter season

How to Spot Ice Dams


January 26, 2026


Winter weather brings cozy nights by the fire, but it also brings potential hazards to your home’s exterior. One of the most destructive winter issues for homeowners is the formation of ice dams. At JM Roofing and Siding, we believe that catching these icy intruders early is the best way to protect your roof and your wallet.

An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow (water) from draining off. The water that backs up behind the dam can leak into a home and cause damage to walls, ceilings, insulation, and other areas.

Visual Signs of Trouble

The most obvious way to spot an ice dam is by looking up. Do you see thick bands of ice forming along the eaves of your roof? While icicles can be pretty, they are often the first red flag.

Watch for these key indicators:

  • Icicles on the Edge: While small icicles are normal, large, heavy icicles hanging from your gutters or eaves often indicate trapped water.
  • Ice on Siding: If you see ice glazing over your exterior siding or accumulating behind gutters, water is likely backing up.
  • Blocked Gutters: If your gutters are completely filled with solid ice, snowmelt has nowhere to go but backward under your shingles.

Interior Warning Signs

Sometimes the damage starts before you notice the ice outside. Keep an eye on your attic and upper-floor ceilings during freezing weather.

  • Water Stains: Yellow or brown water spots on ceilings or near the corners of walls suggest water has already penetrated the roof deck.
  • Damp Insulation: If you inspect your attic and find wet insulation, it’s a sign that the roof’s seal has been compromised by standing water.

Why You Must Act Fast

Ignoring an ice dam won’t make it melt faster. The longer water sits trapped on your roof, the higher the risk of structural rot and mold growth. Addressing these signs immediately can save thousands in repairs. If you spot these warning signs, don’t wait for the spring thaw—call a professional to assess the situation safely.

Choosing The Right Roofing Contractor For Your Fairfield County Home

When it comes to ensuring your roof lasts and is safe for your family, you need to hire the best contractor possible. The experts at JM Roofing and Siding are licensed and insured to serve you in Norwalk, Connecticut, and the surrounding areas. 

Contact us today for a free estimate!