Syracuse and the surrounding Onondaga County area
Ice Dam Prevention, Eave Protection and Attic Ventilation
Stop the ice that builds at your eaves every winter by fixing the heat loss and ventilation behind it, not by chipping at the roof again each February.
What Ice Dams and Ventilation covers
An ice dam is a heat problem that shows up as a water problem. Heat escaping into the attic warms the roof deck, snow melts on the upper slope, the meltwater runs down to the cold overhang beyond the heated walls and refreezes, and the ridge of ice that grows there holds standing water back under the covering until it finds a way in. Syracuse averages 123.8 inches of snow a year, an inch or more sits on the ground on around 60 days of a normal winter, and the temperature crosses freezing in both directions roughly 84 days a year. Those three numbers are the whole mechanism. The New York State Department of Health names ice dams and insufficient attic ventilation among the moisture sources that cause mold in homes, which is why this work is a mix of air sealing, ventilation, eave detailing and drainage rather than roofing alone.
- Attic inspection for the heat paths that feed the dam: open chases, recessed lights, bath fans discharging into the roof space, an uninsulated hatch
- Air sealing of the attic floor within the roofing scope, and coordination with an insulation contractor where the work goes beyond it
- Balanced ventilation: soffit intake cleared and opened, baffles installed, ridge or gable exhaust matched to it
- Ice barrier membrane installed at the eaves and valleys when the covering is off, to the depth the code sets
- Metal valleys, drip edge and eave detailing built for backed-up water rather than running water
- Gutter and downspout renewal, resizing and repositioning of the discharge point
- Repair of what an existing dam has already done: soaked sheathing, rotted fascia and soffit, and stained ceilings along exterior walls
- Careful removal of ice and snow from eaves where the loading is already a risk
- Heated cable at eaves and valleys, as a managed measure where the geometry genuinely cannot be cured
What changes the scope of the work
Every property is different. These are the factors that decide what the job actually involves.
Where the heat is getting into the attic
Every dam starts with a warm deck. Recessed lights, plumbing and flue chases, a bath fan blowing into the attic instead of outside, and a bare loft hatch are the usual sources, and each is cheaper to fix than any roof covering.
Whether intake and exhaust are balanced
A ridge vent with blocked or insulated-over soffits does not ventilate the roof; it draws its air from the heated house below, which makes both the heat loss and the moisture worse. Intake at the eave is the half of the system people leave out.
Whether an ice barrier exists at the eaves at all
On a roof last covered decades ago there is often nothing there. The code requires the barrier to run from the lowest edge of the roof to a point not less than 24 inches inside the exterior wall line, and whether it is required at your address depends on whether your municipality entered YES in its Table R301.2(1), which the state instructs jurisdictions to do where there is a history of local ice damming damage.
How deep the overhang is
The 24 inch measurement is taken inside the exterior wall line, so a house with a deep overhang or a shallow pitch needs several courses of membrane to satisfy the same rule. It is also the geometry that gives the ice the coldest surface to build on.
Roof geometry and orientation
Valleys, dormer cheeks, low-slope tie-ins and north facing slopes hold snow and stay frozen while the rest of the roof clears. Dams form in the same three places on the same house every year, which is a useful thing to know before anyone starts work.
Where the water goes once it is running
Gutters full of ice, undersized downspouts and discharges that back up against the wall all keep water at the eave. In the combined sewer parts of the city, where a downspout ties into the sewer, changing the drainage is a drainage decision as well as a roofing one.
Whether damage inside has already started
Water backed up under a covering wets the top plate, the wall cavity and the ceiling along the exterior wall. The state health department lists ice dams as a moisture source that causes mold in homes, and once that has begun it becomes a separately regulated trade in New York with its own rules.
How the work runs
Look in the attic before looking at the roof
The cause is nearly always inside. Wet or blackened sheathing, frost on nails, warm air at the hatch, insulation compressed against the soffit and daylight that should not be there all tell the story faster than a ladder does.
Measure the ventilation you actually have
Not the vents you can name, the net free area you can prove, counted at intake and exhaust separately. Most houses that dam badly are short of intake.
Seal and insulate before adding vents
Ventilation removes heat that reaches the attic. Air sealing stops it arriving. Doing them in the wrong order means paying to vent away heat you are still buying.
Balance the system
Soffits opened and baffled so the intake is real, exhaust matched to it at the ridge or gables, and bath and kitchen fans ducted to the outside rather than into the roof space.
Fix the eave detail when the covering next comes off
Ice barrier from the lowest edge of the roof to at least 24 inches inside the exterior wall line, metal valleys, and a drip edge and gutter arrangement that assumes ice. Doing this during a replacement costs a fraction of doing it as its own job.
Deal with the water once it is moving
Gutter capacity, downspout size and where the discharge lands, so that meltwater leaves the eave instead of standing at it.
Manage what cannot be cured
Some geometry, a valley over an unheated entry, a dormer against a main slope, cannot be fixed by air sealing alone. That is where heated cable earns its place, as a managed measure with a plan behind it rather than as the first answer.
When you may not need this at all
- If you have had one bad ice winter in ten, after a record snow year, you may have had a weather event rather than a roof defect. Look at whether the same three spots dam every single year before spending money.
- The cheaper half of this work is often not roofing at all. Air sealing and attic insulation are frequently the fix, and an energy audit or an insulation contractor may be the right first call rather than a roofer.
- If the ceiling stain is at an interior wall rather than along the exterior wall line, ice damming is probably not what is happening, and the leak should be traced conventionally.
- If a replacement is already due, wait and do the eave detail then. Ice barrier and valley metal cost far less installed while the covering is off than as a separate operation.
- Heated cable treats the symptom. Where the heat loss can be fixed, fixing it is the better spend, and anyone offering cable before they have been in your attic has skipped the diagnosis.
- If your roof is over an unheated space such as a detached garage or a porch with no room above, dams are unlikely there because there is no heat to melt the snow in the first place.
What is out of scope
- Whole-house insulation and energy retrofit programs, which are their own trade even where the roofing scope touches the attic floor.
- Interior repair after a dam has leaked: plaster, drywall, ceilings and decoration.
- Mold remediation. New York regulates it separately and the removal work belongs to that trade, not to a roofer.
- Electrical supply, circuits and outlets for heated cable, which is an electrician's work.
- Seasonal roof snow clearing contracts.
- Any claim that a given measure will prevent ice forming in every winter this area produces.
Where we arrange this work
- Ice Dams and Ventilation in Syracuse
- Ice Dams and Ventilation in East Syracuse
- Ice Dams and Ventilation in Liverpool
- Ice Dams and Ventilation in Cicero
- Ice Dams and Ventilation in Clay
- Ice Dams and Ventilation in DeWitt
- Ice Dams and Ventilation in Jamesville
- Ice Dams and Ventilation in Manlius
- Ice Dams and Ventilation in Fayetteville
- Ice Dams and Ventilation in Camillus
- Ice Dams and Ventilation in Baldwinsville
- Ice Dams and Ventilation in Skaneateles
- Ice Dams and Ventilation in Solvay
Frequently Asked Questions
Why does my house grow icicles when the house next door does not?
Because of what is happening under your roof, not above it. Heat leaking into the attic warms the deck and melts snow on the upper slope; the water runs to the overhang, which sits beyond the heated walls and stays cold, and refreezes there. A house with a well sealed and well ventilated attic keeps its roof deck close to outdoor temperature, so the snow simply stays snow. Same street, same weather, different attic.
Will more insulation fix it on its own?
Usually not on its own, but it is a large part of it. Insulation slows heat moving through the ceiling, while air sealing stops warm air pouring through gaps around lights, chases and the hatch, and ventilation carries away whatever heat still gets up there. Skipping the air sealing is the most common reason a house that has been insulated still dams.
I have a ridge vent already. Why is it still happening?
Very often because there is no intake to feed it. A ridge vent needs matching soffit intake, and if the soffits are painted shut, blocked with insulation or were never opened, the vent draws its air from the heated house below instead. That makes the attic warmer and wetter rather than cooler and drier. Check the intake before adding more exhaust.
Should I chip the ice off myself?
Chipping and hacking damages the covering underneath, and it puts you on a ladder against an iced eave in February, which is how people get hurt here every winter. Pulling snow off the lower few feet of the roof from the ground with a roof rake, after a heavy fall, takes away the material the dam is made from and is far safer. Where ice has already built up and has to come off, it is work for people set up for it, with steam rather than a hammer.
Is ice barrier membrane required on my roof?
It depends on your municipality, and there is a direct way to find out. The state instructs each authority having jurisdiction to enter YES in the ice barrier underlayment column of its Table R301.2(1) where there is a history of local damage from ice damming, and that entry is what triggers the code requirement. Call your own code office and ask that one question. Where it applies, the barrier must run from the lowest edge of the roof to at least 24 inches inside the exterior wall line.
Can ice dams cause anything worse than a stain?
Yes, which is why the cause is worth fixing rather than the symptom. Backed-up water wets sheathing, the wall top plate, insulation and the ceiling along the exterior wall, and the state health department lists ice dams among the moisture sources that cause mold in homes. Wet insulation also stops insulating, which feeds the heat loss that made the dam.
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