Ice Dams and Roof Snow in Buffalo: A Safety-First Homeowner Guide

What an ice dam is

An ice dam is a ridge of ice along the lower edge of a roof. The National Weather Service describes how it forms: heavy snow on the roof melts during the day and refreezes when temperatures drop overnight. After several days of melting and freezing, water and ice can work up under the shingles until water gets into the attic and then the ceilings, walls, and contents below.

FEMA's snow load guidance adds the structural side: when snow melts between storms and the roof drainage is blocked, ice dams create a concentrated load at the eaves and make it harder for a sloped roof to shed snow. Rain falling on a snowpack soaks the snow and adds weight too.

Why Buffalo roofs get ice dams

Buffalo winters bring both of the things ice dams need: lots of snow and frequent swings around freezing. The National Weather Service office in Buffalo describes Western New York winters as cloudy, cold, and snowy, but changeable, with frequent thaws and rain. It notes that over half of the annual snowfall comes from lake-effect snow, which is very localized, and that areas south of Buffalo get much more lake-effect snow than places to the north. The lake snow machine can start as early as mid November, peaks in December, then virtually shuts down after Lake Erie freezes in mid to late January.

The normal seasonal total at Buffalo is 95.4 inches, from the NWS Buffalo 1991-2020 climate normals. Your street can see far more or far less in a single storm, because lake-effect bands are narrow.

Rake from the ground after each storm

The National Weather Service suggests keeping roof snow to a minimum with a long-handled roof rake that lets you stand on the ground and pull snow off the roof. Keeping heavy snow off the roof reduces the chance of both ice dams and roof failure from the weight.

• Use a non-metal rake. FEMA warns that metal snow rakes can damage roofing and pose an electrocution risk. Keep any rake well away from power lines.
• Stay out of the slide zone. Roof snow can slide at any moment. Stand far enough from the eave to be outside its sliding range, and watch for falling icicles.
• Leave a thin layer. FEMA notes that scraping a roof down to the shingles can damage the roof covering; leave a couple of inches of snow.
• No sharp tools. Do not chip at ice dams with picks, hatchets, or shovels. FEMA advises against sharp tools on a roof.
• Pace yourself. The National Weather Service warns that shoveling heavy snow strains the heart, especially if you are not in good health. Take breaks or get help.

Never climb onto a snowy roof

FEMA calls roof snow removal a dangerous activity that should only be done by qualified people following safety protocols, including fall protection where it applies. Snow hides skylights, edges, and ice. If the snow cannot be reached safely from the ground, hire a qualified roofing or snow-removal contractor and ask how their crew works safely on a snow-covered roof.

Do not use a ladder against an icy gutter or eave, and do not send anyone up during a storm or while snow is still falling.

Warning signs of an overloaded roof: when to leave

FEMA lists these signs that a roof may be overstressed by snow. Wood and steel framing often show sagging before they fail:

• Sagging ceilings, or ceiling boards or tiles that drop or bulge
• Popping, cracking, or creaking noises
• Sagging roof framing or sheathing
• Doors or windows that can no longer be opened or closed
• Cracked or split wood framing
• New cracks in walls or masonry
• Severe roof leaks

If you see any of these, get everyone out of the house. FEMA's guidance is to evacuate promptly and contact your local building authority or a qualified design professional, such as a structural engineer, for an inspection. If anyone is in immediate danger, call 911. Do not go back in, and do not try to clear the roof yourself, until a professional says it is safe.

If an ice dam is already leaking

1. Stay off the roof and the ladder. A leak is not a reason to climb.
2. Inside, move belongings away from the drip and catch the water.
3. If water is near light fixtures, outlets, or the electrical panel, stay away from it and call a qualified electrician.
4. Take photos of the ice dam from the ground and the damage inside for your records and any insurance claim.
5. Call a qualified roofing contractor to remove the ice dam and check the roof.
6. If the leak comes with sagging, cracking sounds, or sticking doors, treat it as an overloaded roof and leave the house.

The long-term fix: attic insulation and ventilation

Raking treats the symptom. Ice dams start when heat from the house warms the roof deck and melts the snow above it. The National Weather Service suggests evaluating the insulation and ventilation in your attic: insulation keeps heat in the living space, and airflow from the eaves or soffits along the underside of the roof and out through the roof vents keeps the attic cold enough to limit the melt and refreeze cycle. It notes that most experts recommend attic insulation of at least R-30, with R-38 preferable in northern climates.

A reputable roofing or insulation contractor can check whether insulation is blocking soffit vents and where warm air is leaking into the attic. The best time to ask is before the lake-effect season, not during it.

Gutters, downspouts, and vents

• Before the snow: clean leaves, sticks, and debris out of gutters and downspouts so meltwater can flow off the roof, as the National Weather Service suggests.
• All winter: keep gutters and downspout outlets clear of snow and icicles when you can reach them safely from the ground.
• Furnace and dryer vents: sidewall vents can drift over. Erie County health officials advise clearing exterior exhaust and furnace vents, and the National Weather Service says to keep the outside vent of a carbon monoxide detector clear of snow. If you have an upstairs gas furnace that vents out the roof, the National Weather Service notes you may need to turn it off until the snow melts off the roof; ask your heating contractor.
• Carbon monoxide alarms: test them before the season. Blocked vents are one way carbon monoxide builds up indoors.

For the full before-and-after list for a snowstorm, see winter storm home prep. If the storm takes out the power, see winter power outage home prep. For meltwater that reaches the basement, see what to do if your sump pump fails. Print the general Weather-Ready Home Checklist or the Storm Power Outage Home Checklist PDF, or browse the full printable checklist library. The rest of the season is laid out in the Buffalo winter checklist.

Why an app, not another weather alert

A Lake Effect Snow Warning tells you snow is coming. It does not remind you that the roof rake is buried in the garage or that the furnace vent on the side of the house drifts over. HomeGuard Weather is designed to turn a snow and deep-cold forecast into a short checklist for your house, such as checking exterior vents. It is software only, with no sensor or device to install. It cannot measure the snow on your roof, judge whether a roof is safe, or replace a roofer, an engineer, or official alerts. Weather-triggered reminders are planned for launch and will be tested in the beta.

For the full launch scope and pricing, see HomeGuard Weather features & pricing.

Sources

• National Weather Service, Preventing Roof Ice Dams: how ice dams form and leak, roof rakes from the ground, gutters and downspouts, attic insulation (R-30 to R-38) and ventilation.
• FEMA Snow Load Safety Guidance (FEMA P-957 flyer): warning signs of an overstressed roof, evacuate and call a building authority or design professional, ice dams and rain-on-snow loads, non-metal rakes from the ground, sliding snow, leaving a couple of inches, no sharp tools, removal only by qualified people with fall protection.
• NWS Buffalo, Buffalo climate narrative: lake-effect share of snowfall, areas south of Buffalo, mid November to January season, frequent thaws and rain.
• NWS Buffalo, 1991-2020 climate normals: 95.4 inches seasonal snowfall and the monthly normals in the table.
• National Weather Service, during a winter storm: overexertion while shoveling, furnace vents blocked by drifts, upstairs gas furnaces that vent through the roof.
• National Weather Service, before a winter storm: keep the carbon monoxide detector's outside vent clear of snow.
• Erie County Department of Health, winter storms and extreme cold: clear exterior exhaust and furnace vents.

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