What an ice dam is
Heat from the house warms the roof deck, snow melts and runs down to the cold eaves, then freezes again. That ridge of ice traps more meltwater behind it, which backs up under the shingles and into the house.
Signs to look for
Big icicles along the gutters, a thick band of ice at the roof edge, water stains on ceilings near outside walls, and peeling paint around windows are all common signs.
Quick fixes vs. real fixes
Raking snow off the bottom few feet of the roof from the ground can help during a storm. Avoid chipping ice with tools; it damages shingles.
The lasting fix is keeping the roof deck cold and the eaves sealed: enough attic insulation, good ventilation, and ice and water shield under the shingles at the eaves. If your roof doesn't have that, it's worth adding at your next replacement.
Already leaking?
Put a bucket under the drip, move valuables, and take photos. Then send us a quote request and mention it's leaking. Once it's safe to get on the roof, we'll find where the water is getting in.