An ice dam is one of those problems that looks like winter just being winter, right up until the water shows up on your ceiling. The ridge of ice along the eaves is a sign of what is happening higher up on the roof, and it is worth understanding before a January thaw finds a way inside.
W Contracting Roofing is a Saskatoon roofing company, and stopping ice dams is part of how we detail a roof.
Ice dams are common on Saskatoon homes because our winters give them everything they need: snow that sits for months, and a stretch of warm days and cold nights that melts and refreezes it over and over. Here is what is actually going on, how to catch it early, and what keeps it from coming back.
What an ice dam actually is
Snow lands on the roof and stays. Heat leaking up from the house warms the roof deck under that snow, so the underside of the snow melts even when it is cold out. The water trickles down the slope until it reaches the overhang past the exterior wall, which stays cold because there is no heated room beneath it. There the water refreezes, and a ridge of ice builds along the eaves. Once that ridge is in place, the next round of meltwater pools behind it with nowhere to drain, and standing water on a roof does what standing water always does: it works its way under the shingles and into whatever is below.
Why Saskatoon roofs get them
A long prairie winter keeps a snow load on the roof for months at a time, and the swing between a sunny afternoon and a forty below night is exactly the melt and refreeze cycle a dam feeds on. Older homes tend to leak more heat into the attic, which makes the roof deck warmer than it should be. North-facing slopes, valleys where two roof sections meet, and the stretch above a warm room like a bathroom or kitchen are the usual spots to watch.
How to spot one before it leaks
You can see most of the warning signs from the driveway. Look for a thick band of ice along the eaves, large icicles hanging off the gutters, and eavestroughs packed solid with ice. Inside, a damp patch or a brown stain on a top-floor ceiling, or on the wall just below the eaves, means water is already getting past the roof. If you can get into the attic safely, frost on the underside of the sheathing or damp insulation near the eaves is the same story told from the other side.
The real fix is heat and air, not the roof
It is tempting to treat an ice dam as a roof problem, but most of the time the roof is doing its job and the attic is the culprit. Warm air escaping through a poorly sealed attic hatch, gaps in the insulation, or a bathroom fan that vents into the attic instead of outside all heat the roof deck and start the melting. Keeping the attic cold and well ventilated so the roof deck stays the same temperature end to end is what stops the snow from melting unevenly in the first place. It is quieter work than it sounds, and it is usually where a recurring dam gets solved for good.
What clean eavestroughs have to do with it
When the eavestroughs and downspouts are full of leaves or already iced up, meltwater has nowhere to go, so it sits at the edge of the roof and freezes faster. Clearing them out in the fall is one of the simplest things that helps, which is why it is on every winter roof checklist. If your eavestroughs, soffit and fascia are sagging, undersized or pulling away from the house, they will keep feeding the problem until they are put right.
What not to do
Do not climb up and chip at the ice with a hammer, an axe or a garden spade. It feels productive and it wrecks the shingles underneath, which turns a winter nuisance into a spring repair. Do not pour rock salt straight onto the roof either, since it stains the shingles and runs off into the plants below. And do not get onto an icy, sloped roof at all. From the ground, a roof rake used gently to pull the snow off the lower few feet takes away what the dam feeds on, and that is as far as it is worth going on your own.
When to call a roofer
Call when water is already coming inside, when the same dam builds in the same place every winter, or when a leak keeps returning after a cold snap. We can trace where the water is actually getting in, which is rarely right under the stain, and handle the roof repair for damaged shingles or failed flashing. If the roof turns out to be worn past the point where a patch makes sense, we will talk through roof replacement honestly rather than push you into one. Water coming in during a storm or overnight is covered in our emergency roof leak steps.