Icicles or ice along the roof edge

A ridge of ice along the roof edge, often with long icicles, is the sign of an ice dam. Snow melting higher on a warmer roof refreezes at the cold edge, and water can back up under the shingles. Removal deals with the ice now; sealing and insulating the attic stop it returning.

Updated

Fixes it now

Ice Dam Removal

An ice dam is a ridge of ice at the roof edge that traps melting snow, which can back up under the shingles into walls and ceilings. If water is already coming in, the Minnesota Department of Commerce says to hire a removal service that uses steam, and to avoid chipping, chemicals or open heat.

Fixes the cause

Attic Insulation & Air Sealing

Air sealing and attic insulation fix the cause of most ice dams: heat escaping into the attic. University of Minnesota Extension says to seal the leaks first, then add insulation. The state energy office recommends at least R-50 where space allows, starting with an energy assessment that finds the leaks.

Roof & Attic Ventilation

Attic ventilation lets outside air through the attic to dry it and clear summer heat. It is not a cure for ice dams on its own. University of Minnesota Extension does not recommend powered attic fans for ice dams in Minnesota, and the state energy office says added roof vents often make them worse.

Ice Dam Prevention & Heat Cables

Heat cables are wires laid along the roof edge to melt paths for water. The Minnesota Department of Commerce advises against installing them, saying they shorten the life of a roof and add to energy costs. The fix for the cause is sealing attic air leaks and adding insulation.

What to do today

  1. Look inside for stains on ceilings and outside walls below the ice.
  2. Rake snow off the lower roof from the ground if you can do it safely, accepting that a rake can scuff shingles.
  3. If water is coming in and you cannot wait, a channel melted through the dam with tap water on a warm day lets water drain for a few days.
  4. Do not chip at the ice or climb onto a winter roof.

When it is an emergency

Water running into the house is an emergency. Call a removal service that uses steam, and move belongings away from the leak.

Sources

Frequently asked questions

Can I knock the icicles and ice off myself?

University of Minnesota Extension warns that anyone working on a roof in winter risks injury and damage. The state energy office advises against chipping or using chemicals or heat on the ice. Rake snow from the ground if it is safe, and leave the ice to a professional.

Why does the ice always form at the edge?

The edge sticks out past the heated walls and stays as cold as the outside air, while the roof above the house is warmed from inside. Snow melts higher up and freezes when it reaches the cold edge.

How to get a quote

Pick a business from the list and use the contact form or phone number on its own website. Asking two or three lets you compare. Cold Home Guide does not take quote requests.