Ice dams are one of winter’s quieter troublemakers—polite on the outside, destructive on the inside.

What is an ice dam?
An ice dam forms when snow on a roof melts, runs down to the colder eaves, and refreezes. Over time, this creates a ridge of ice along the roof edge. Think of it as a frozen traffic jam that stops water from draining where it should.

Why they form
Ice dams are usually caused by uneven roof temperatures, most often from:

• Heat escaping from the home into the attic
• Inadequate insulation or ventilation
• Repeated freeze–thaw cycles after snowfall

Warm roof + cold edge = ice dam. Winter math is unforgiving.

Why they’re a problem
Once water is trapped behind the ice dam, it has only one place to go: back up under the shingles. This can lead to:

• Interior leaks and ceiling stains
• Damaged insulation
• Mold growth
• Rotting roof decking and fascia

In short, a small ridge of ice can turn into a very large repair bill.

Prevention basics
The most effective defenses include:

• Proper attic insulation to reduce heat loss
• Adequate roof and soffit ventilation
• Timely snow removal from roof edges
• Monitoring during heavy snow and warming trends

Why home watch matters
Ice dams often develop quietly while homeowners are away. Regular exterior checks allow early detection—before water finds its way inside and starts redecorating your ceilings without permission.