Ice Dams in Winter
What’s Happening
Ice dams form when heat escaping through your attic melts snow on the upper roof, and that water refreezes at the cold eaves – building a ridge of ice that traps meltwater and forces it back up under your shingles. The water that gets underneath doesn’t stay on the roof. It finds its way into your attic, your insulation, your ceilings, and your walls. This is almost always a roofing and attic insulation problem, not simply a weather problem.
Once an ice dam is in place, every warm day followed by a cold night makes it worse. The water pooling behind the dam has nowhere to drain, so it sits against shingles, flashings, and underlayment – materials designed to shed water moving downward, not water sitting still. Left alone through a single winter, ice dams can lift shingles, rust flashings, saturate roof deck boards, and drive moisture deep enough to stain ceilings or feed mold in wall cavities. The ice itself looks like a winter curiosity. The damage it’s doing inside the wall is a different story.
Why It Happens
Inadequate Attic Insulation
This is the root cause in the majority of ice dam situations. When your living space is poorly separated from the attic floor, heat rises straight through and warms the roof deck from the underside. The tell is simple: if the snow on the top third of your roof melts faster than the snow near the eaves, heat is escaping unevenly through the attic. Ice forms right at the line where the warm deck meets the cold overhang.
Blocked or Insufficient Attic Ventilation
A properly ventilated attic flushes cold outside air through continuously – ridge vents at the top, soffit vents at the bottom – keeping the deck temperature close to the outdoor air temperature. When those vents are blocked by insulation, debris, or snow, warm air stagnates against the deck. You can sometimes spot this from the attic: if it feels noticeably warmer up there than it should in winter, or if you see frost condensation on the underside of the sheathing, ventilation is likely the issue.
Ice and Water Shield Gaps or Aging Underlayment
Building codes in cold climates require a self-adhering waterproof membrane along the eaves and in valleys – specifically because ice dams happen and water needs a secondary line of defense when they do. On roofs more than fifteen to twenty years old, that membrane can dry, crack, or lose adhesion. You won’t see this from the ground, but if meltwater is getting into the house despite no visible shingle damage, the underlayment is a strong suspect.
Flashing Failures at Valleys and Penetrations
Ice expands and contracts. Over several winters, that movement works on step flashings, valley flashings, and the seals around chimneys, pipes, and skylights – lifting edges and opening gaps that water finds quickly. If the leak or staining inside your home appears near a wall, chimney, skylight, or in a valley line rather than in an open field of ceiling, a flashing failure is likely contributing alongside the dam itself.
What to Do Right Now
- Document everything with photos. Walk around the house and photograph the ice dam, any icicles, any water staining on soffits or interior ceilings, and the pattern of snow melt on the roof surface. This record helps a technician understand what happened even after conditions change.
- Don’t climb onto the roof. A snow- or ice-covered roof is one of the most dangerous surfaces a person can stand on. Your local Ridgeline Roofing Co. team has the equipment and training for this work. Standing at grade and calling for help is the right call.
- Move valuables out from under active leaks. If water is getting in, protect furniture, documents, and electronics. A plastic bin and some towels do a lot of work while you wait for the crew.
- Avoid roof rakes used aggressively near flashings or skylights. A long-handled roof rake used carefully from the ground to pull snow back a few feet from the eave edge can reduce the water feeding a dam – but stop before you hit any penetration, vent, or flashing. Metal tools dragged across shingles and flashings cause their own damage.
- Turn off attic fans or whole-house fans. Any device pulling warm interior air into the attic speeds up the heat-escape cycle that’s building the dam. Shut them off until the roof is assessed.
How We Fix It
When your local Ridgeline Roofing Co. team arrives, the first step is a real inspection – from the roof, not the driveway. A technician goes up, documents conditions with photos, and traces where water has entered or is likely to enter. That inspection drives everything that follows.
Most ice dam repairs touch two of our service areas: Roof Repair and, where the underlying cause is a ventilation or insulation shortfall that left the roof vulnerable, a conversation about what changes would prevent a repeat next winter. The repair itself typically means replacing or supplementing the ice-and-water shield along the eaves, resealing or replacing flashings, and addressing any shingle or deck damage the water caused. On straightforward jobs, we complete the work in a single visit.
Before any work begins, you get a written estimate with the exact number. The number on the estimate is the number on the invoice – no surprises. And every repair is covered by our 90-Day Done Right Promise: if it’s not right, we come back and make it right, no paperwork, no arguing. That’s in writing too.
Frequently Asked Questions
An ice dam is actively pushing water under your shingles every time temperatures rise above freezing, so waiting carries real cost. Water that reaches the roof deck, insulation, or framing doesn’t dry out on its own – it stays wet, loses its structural value, and can grow mold. If you’re seeing interior staining or dripping, that’s water already inside the assembly, and the sooner the dam is addressed, the less secondary damage you’re looking at. Call (844) 563-1816 – a live person will pick up and help you figure out how quickly you need someone on site.
Our phones are answered by a live person 24 hours a day, seven days a week – nights, weekends, and the middle of a storm included. Your local Ridgeline Roofing Co. team will assess your situation and get you on the schedule as quickly as conditions and crew availability allow. Call (844) 563-1816 right now and tell us what you’re seeing.
Many standard homeowner’s policies cover interior damage caused by ice dams as a sudden and accidental loss – but the roof repair itself is often treated differently, especially if the insurer determines the underlying cause was deferred maintenance or inadequate insulation. Your local Ridgeline team documents everything with photos from the roof, which gives you solid evidence for any claim. We’d recommend calling your insurer to open a claim early, then calling us so the damage is documented before conditions change.
Both, and they’re connected. The ice dam is the symptom; the heat escaping through your attic is the cause. A repair that only addresses the shingles and flashings will help, but if the insulation and ventilation conditions that created the dam aren’t corrected, you’re likely to see the same problem next winter. A proper inspection looks at the whole picture – and that’s exactly what our technicians do when they get on your roof.
Get It Fixed
Call (844) 563-1816 right now – a live person will answer. Your local Ridgeline Roofing Co. team will schedule an inspection, get on your roof, document everything, and hand you a written estimate before any work starts. We’ve been standing behind local roofs since 1984, and we’ll stand behind yours.
Written by Pete Navarro, Owner at Ridgeline Roofing Co., serving local communities across the country since 1984.