Icicles and Roof Snow Slides Near Entrances: Managing the Hazard Zone

Can falling snow and icicles really hurt someone?

Yes, and the sources do not soften it. A paper on snow guards for metal roofs, reprinted by the roof consultants' organization IIBEC, states that sliding snow and ice can damage property, kill people and overload lower roofs.

We have no statistics to offer about how often this happens in Montana and we are not going to invent any. It is enough to know that the weight involved is real and that the danger is greatest exactly where people pause, such as at a door, under an awning, or beside a car while finding keys. Treat a loaded eave over a doorway as a real hazard, even if nothing has come down so far this winter.

Why does snow slide off some roofs and not others?

Metal is the main difference. The IIBEC paper says metal is slippery, and that with no obstructions and open space below the eaves, snow on the roof is inclined to slide off. It notes frictional resistance near zero when snow is close to the freezing point, which is why a warm afternoon after a cold storm is when a roof can let go. That is a useful thing to remember in western Montana valleys, where days often swing above and below freezing.

Sliding is not all bad. The same paper says it can reduce ice damming, leaks, and the intensity and duration of roof snow loads. It becomes a problem when what is below the eave is a door, a walk, a parking space, a lower roof, a gas meter or a deck, and the paper specifically notes that sliding snow has also displaced or sheared off plumbing stacks and other roof penetrations. Look at your roof with that in mind: where does each slope drain, and what is under it?

Why do icicles form over the front door?

University of Minnesota Extension's explanation of ice dams gives the mechanism: nonuniform roof surface temperatures. Snow melts on warmer upper areas of the roof and refreezes at the colder edge. Heat escaping from the house is the main driver, and warm air leaking through ceiling penetrations into the attic is often the major cause. The Minnesota page itself deals with ice dams and does not discuss icicles, but where meltwater runs to a cold eave and drips off, that is the same setup that makes them, and heavy icicles are worth reading as a prompt to find out why water is moving on your roof.

Snow guards can make this specific problem worse in some layouts. The IIBEC paper says guards near the eaves can hold snow that extends over the fascia, with meltwater running beneath it and forming dangerously large icicles at the end of that overhang. That is one reason roof fixes need to come from someone looking at your actual roof. Our article on ice dams in Montana homes covers causes and prevention in more depth.

How do you find the drop zone at your entrance?

Stand back after a storm and look. The zone runs along the eave of any slope draining over a door, walk or parking area, and on a metal roof it can reach out past the eave because sliding snow has momentum when it leaves the edge. Previous winters leave clues: a compacted strip along the building, a dented gutter, broken shrubs below the eave, or a line where the plow always finds a hard ridge.

Notice the door itself. A door in a gable end, where the roof slopes away to each side, is usually out of the line of fire. A door under the low edge of a roof slope is directly in it. Then look at what else is down there. Parked cars, a gas meter, a dryer vent and an outdoor faucet can all be damaged, and a covered entry roof below a larger roof takes the load of everything that comes down onto it.

What can you do from the ground to protect people?

Start with where people walk. If there is a choice of doors, use the one out of the drop zone during heavy-snow periods, and tell guests or customers. Mark a temporary route around a loaded eave with cones or stakes and a plain sign, and do not park in the zone. If a path has to run along the wall, consider moving it a few feet out for the winter and clearing there. On a commercial site, make sure the snow crew knows which door is out of use, and keep that route clear.

Stay out from under while you work. When you shovel along a wall below a loaded roof, you are in the drop zone, and so is anyone working for you. Keep a clear look upward, do not stand under hanging ice to knock it off, and take a longer route with the snow blower instead of working directly under the eave if the roof looks ready to go. Keep people away from large icicles instead of trying to knock them down, and leave removal to a professional. University of Minnesota Extension is direct that anyone on the roof in winter, or doing roof work from below, risks injury, and it advises hiring professionals.

Then look at the refreeze below. Meltwater dripping onto a walk or a step in the afternoon becomes ice by evening, and that spot can ice over again day after day. Clear it, and treat it with sand or a thin melting product. Our black ice guide explains why that spot keeps refreezing. Downspouts that dump onto a walk deserve the same attention, and extending them away in the fall is a simple fix.

Where should snow from the roof and walk go?

Away from the door, and not in a pile that makes the drop zone worse. Snow that slides off a roof can build up against a wall or over a window well, and adding shoveled snow on top of it does not help. Ask what is under it too, because a pile sitting on a gas meter, against siding, or over a vent is a separate problem. Our guide on where to pile snow walks through what to avoid, and our winter tree care and snow load article covers what heavy snow does to the plants around a house.

Should you pull snow off the roof yourself?

We would not start there. University of Minnesota Extension says a roof rake and push broom can be used to remove snow but may damage roofing materials, and repeats that anyone working on or below a winter roof risks injury. OSHA, writing for employers, says snow removal tasks must be assessed for hazards, that a surface weighed down by snow must be inspected by a competent person before access, and that methods that do not involve workers going on roofs should be used when and where possible. It also warns that snow-covered rooftops can hide hazards such as skylights.

Pulling snow off a roof also puts you exactly where the snow is about to land. If you are worried about the load on the structure, see when roof snow needs removing, and talk to a roofer or structural professional for your building. Do not get on a roof because a neighbor did.

Who should you call about snow guards and heat loss?

A qualified roofing contractor for snow guards and a weatherization or insulation professional for heat loss. We do neither of those. The IIBEC paper is a good illustration of why this is not a hardware-store job: it says guards can protect just part of a roof, such as an entrance below the eaves, but that snow beside a guarded area can add significant load, that multiple rows spaced up the roof work better than a single strong row at the eave, that the lowest row should sit upslope of the heated wall and not on the overhang, and that the allowable load should be less than half of any reported failure test load.

For the heat side, University of Minnesota Extension recommends sealing air leaks first, then considering added insulation, and suggests a blower door test and an infrared inspection by a weatherization professional. Those steps reduce the melting that feeds the ice in the first place, and they are the kind of fix that lasts for more than one winter.

What about trees above a roof or entry?

Trees add their own version of this. Limbs loaded with wet snow can come down on the same spots, and they can also drop snow onto a roof or a walk well after the storm has ended. If a limb hangs over a door or a walkway, a clearance prune during dormancy is worth arranging, and this is work we do. See dormant pruning, and if you are unsure of a limb, a tree health and risk assessment will sort out which ones are a real concern.

How can a snow service help around entrances?

We clear from the ground. That means walkways and entry paths, ice management on the spots that refreeze, and an agreed route that keeps our crew and your visitors out of the drop zone. Tell us about any eave that sheds on a door or walkway when you set up residential snow removal or commercial snow removal, since it changes how and where we work. Our snow and storm services page describes the rest, and this article is part of our Montana Winter Property Guide.

Call HJ Property Care & Tree Service at (406) 215-7319 or reserve a spot on a 2026-27 snow route before the first storm.

More resources