Every winter we get calls about water coming through a ceiling in January. Most of the time it's an ice dam.
How ice dams form
Warm air from the house leaks into the attic and heats the underside of the roof. Snow on top melts, runs down, and refreezes at the cold edge over the eaves. That ridge of ice traps the next round of meltwater, and the water backs up under the shingles.
Signs you might have them
- Big icicles hanging off the gutters
- A thick ridge of ice along the bottom edge of the roof
- Water stains or peeling paint on ceilings near outside walls
- Frost or damp spots in the attic
What actually helps
Clean gutters help, but they don't fix the cause. The root cause is almost always a mix of air leaks, not enough insulation and unbalanced ventilation. Minnesota code targets R-49 attic insulation and requires balanced soffit and ridge ventilation.
- Seal air leaks into the attic: light fixtures, attic hatches, bath fans
- Insulate to keep the roof deck cold
- Ventilate so cold air flows in at the soffits and out at the ridge
- Ice and water shield at the eaves, the backstop that keeps backed-up water out
A roofer who replaces your roof without checking the ventilation is treating the symptom. We verify intake and exhaust on every roof we install.
Please don't chip the ice
Hammering or shoveling ice off the roof tears shingles and is harder on your back than it looks. If you have an active leak, call us.
Frequently asked questions
Is an ice dam a roofing problem or an insulation problem?
Usually insulation and ventilation. The roof is where the damage shows up, but the cause is warm air reaching the roof deck.
Will a new roof stop ice dams?
A properly built roof with ice and water shield and correct ventilation greatly reduces the conditions that create them, but it doesn't guarantee an ice-free winter if the attic is still leaking heat.
Can you remove an ice dam?
Yes, we help with snow and ice dam removal when water is coming in. The long-term fix is in the attic.
Written by Joey BrueOwner of Joey Roofing and Siding, the family roofing company in Chanhassen since 1983.