Ice dam season in the Capital Region is roughly late January through mid-March. What most homeowners see is water coming through the ceiling near an exterior wall, sometimes staining the drywall, sometimes dripping into a light fixture, sometimes soaking a section of insulation. What they usually assume is that the roof has failed. What’s actually usually happened is more specific — and more addressable.
I want to walk through what an ice dam actually is, why it damages the roof at the eaves specifically, and the three levels of repair that address it. Because the difference between a $1,500 repair and a $22,000 replacement is which level you’re actually at.
What an ice dam is
Snow accumulates on your roof. Warm air from your attic — sometimes because insulation is thin, sometimes because ventilation isn’t working, sometimes just because winter house heat is doing what winter house heat does — warms the underside of the sheathing. Snow directly above the warm portions of the roof melts. Meltwater flows down the slope.
At the eaves, past the exterior wall, the roof is unheated. Meltwater hits that cold section and refreezes. Over several freeze-thaw cycles, a ridge of ice builds up along the eave. That ridge is the dam.
Once the dam is high enough, meltwater from further up the slope pools behind it. It has nowhere to go, and it eventually finds its way under the shingles, past the underlayment, and into the roof deck. From there it can travel a considerable distance — into the fascia, down inside the wall, and eventually into your living space.
The damage is not caused by the ice on top. The damage is caused by liquid water backing up under the shingles because the ice is blocking the flow off the roof.
Level one: the ice-and-water shield rebuild
If the leak is limited to a section of one eave and the underlying sheathing is still sound, the repair is a targeted rebuild of the ice-and-water shield section along that eave.
What we do. Remove the first two or three courses of shingles along the affected eave. Remove the failed or aged ice-and-water shield underneath. Inspect the sheathing for water damage — usually superficial staining, sometimes minor delamination but structurally sound. Install fresh modern ice-and-water shield, six feet up from the drip edge. New drip edge if the existing one is corroded. Reinstall shingles over the fresh membrane.
Cost. Usually $1,200 to $2,800 depending on eave length and how many courses of shingle need to be replaced.
When it’s enough. When the shingle field on the slope is otherwise sound, when the sheathing has minor water staining but no rot, and when the underlying insulation and ventilation situation has been addressed or is going to be addressed separately. This is the majority of ice dam repair jobs we do.
Level two: the insulation and ventilation fix
The ice dam wouldn’t have formed if the attic weren’t leaking heat unevenly. So a real ice dam repair sometimes needs to address the underlying cause on the attic side — otherwise the dam will form again next winter and the repair will get tested again.
What this looks like. Blowing in additional insulation to bring the attic to R-49 or better. Adding insulation baffles at the eaves so airflow isn’t blocked. Confirming soffit vents are open and functioning. Installing a proper ridge vent if the current one is undersized. Sometimes sealing air leaks from the house into the attic through recessed light fixtures or attic hatches.
When it’s needed. When the ice dam is recurrent — you’ve had backup damage in more than one winter — or when the attic is visibly under-insulated when we look. This is an insulation-side repair, not a roof-side repair, but it’s inseparable from the roof problem. Some homeowners do it themselves after we point out what’s needed. Some ask us to include a subcontractor. Some pass on it and accept the risk of another dam.
Level three: the sheathing rebuild
The escalation from level one is when the sheathing itself has failed under years of accumulated ice dam damage.
What this looks like. When we open the eave section, we find sheathing that’s soft, discolored, delaminated, or actively rotten. The repair is no longer just a membrane rebuild — it’s a partial deck replacement. Individual sheathing panels get replaced. Underlying rafter tails sometimes need attention if the damage has reached them.
Cost. $3,500 to $7,000 depending on how much deck needs replacement.
When it’s the answer. When we’ve opened up the eave and found more than we hoped. This is usually a jump-up mid-repair, not something we quote at the start unless the visible signs from underneath already tell us the sheathing has failed.
When ice dam damage is a replacement conversation
The one situation where an ice dam problem becomes a replacement conversation is when the shingle field on the whole slope has aged out anyway. If the field is granule-shot and cracking, and the ice dam has forced our hand at the eaves, doing eave-only work is spending money on a roof that’s about to need everything else too. Sometimes the right answer is to accept that the ice dam sped up the timeline and do the replacement now instead of deferring it two years.
We’re honest about which situation you’re actually in. If eave work is enough, we quote eave work. If the field is done, we quote a replacement. There is no version of this where we do eave work and then come back six months later to sell you the replacement we already knew you needed.
What to do this winter if you see one
If you have an ice dam actively forming and water is coming into the house, don’t try to chip it off yourself — you’ll damage the shingles. Cold-weather emergency service is what we’re for. Same-day tarping, ice-melt application, and preventive steps to stop the immediate flow into your house. Then a proper diagnosis in a weather window when the roof is workable.
Paul Sandul, Elite Contracting. Family-owned. Clifton Park.
Ice dam repair is part of the diagnosis-first repair process walked through in our pillar: The Cohoes Chimney Drip. Service page: Roof Repair.