If you see water stains along an outside wall or near the ceiling edge after a snow, ice dams on your roof are a likely cause, and the repair has two parts: a roof leak repair where the water got in, and a look at why the ice formed in the first place. Stay off the roof and off ladders, and don’t try to chip the ice. Catch the water inside, take photos from the ground, and have a roofer find the source. Our roof repair visits start there: we find where the water is getting in, photograph it and give you a straight answer.
What are ice dams on a roof?
An ice dam is a ridge of ice that builds up along the lower edge of the roof, usually right over the gutters and eaves.
Snow sits on the roof. Heat from the house warms the upper part of the roof deck, and the snow there melts from underneath. That meltwater runs down the roof until it reaches the eaves, which hang out past the warm walls and stay cold. There it refreezes. Each melt-and-freeze cycle adds to the ridge, and before long there’s a wall of ice holding back a pool of water.
Shingles are designed to shed water running downhill. They aren’t built to hold back standing water. When that pool backs up under the shingles, it can work its way to the roof boards and into the house.
Front Range weather can set this up. We get a snow, then a sunny afternoon above freezing, then a hard freeze that night. Heat from the house and from the sun melts the snow on the upper roof, and the overnight freeze turns that meltwater back into ice at the eaves. Each round of that cycle builds the ice.
Signs an ice dam is causing your leak
Look for:
- Water stains or peeling paint near exterior walls, often in the corners of upstairs rooms or along the top of a wall.
- Thick ice along the eaves and gutters, sometimes with icicles hanging off it.
- A leak that shows up on a sunny day after a snow, not during the snowfall itself.
- Wet or frosty insulation in the attic near the outside edges, if you can see it safely from the attic hatch, without stepping on the insulation.
What to do right now (and what not to do)
Do:
- Catch the water inside with buckets and towels, and move furniture and electronics away from it.
- If water is dripping through a light fixture or near an outlet, don’t touch it and keep people and pets away. If a ceiling is bulging or sagging with water, stay out from under it. If you can reach your electrical panel without stepping through water, turn off the breaker for that room. If you’re not sure, call an electrician.
- Take photos and a short video of the stain, the drip and the ice along the roof edge from the ground.
- Call a roofer to look at it.
Don’t:
- Don’t climb onto the roof, or onto a ladder, when there’s snow or ice on the roof or the ground. An icy roof edge is one of the most dangerous places on a house. That’s a job for a trained crew, once conditions allow.
- Don’t stand or park under icicles or ice at the roof edge. Chunks can fall without warning. Take your photos from a safe distance.
- Don’t chip at the ice with a hammer, shovel or ice pick. It’s easy to break shingles, gouge the gutters or tear off flashing, which turns one leak into several.
- Don’t throw salt or chemicals on the roof. Some can damage shingles, metal and plants below.
What roof leak repair looks like after an ice dam
Once the ice melts, the leak often stops. But the water already got under the shingles once, and it can again.
When we come out on an ice dam leak, we:
- Inspect the roof section by section when conditions allow, and photograph what we find, especially along the eaves, valleys and roof-to-wall joints.
- Check the attic for wet insulation, stained roof boards and signs that warm air is reaching the roof deck.
- Look for related damage: lifted or cracked shingles at the eaves, flashing pulled loose, and gutters bent by the weight of the ice.
- Tell you honestly whether this is a repair or a sign the roof is at the point where repairs stop making sense.
- Give you a written scope and price before any work starts.
Some repair work depends on temperature, because shingle sealing and some materials need warmer weather. Sometimes the right move in winter is a temporary fix now and a permanent repair when the weather allows. A temporary fix is meant to limit water until conditions are right for the real repair. It isn’t a guarantee that the leak is fully stopped. We’ll tell you which one you’re getting.
Why ice dams form on some roofs and not others
The difference is usually how much heat is reaching the roof. Common causes:
- Warm air leaking into the attic through gaps around light fixtures, attic hatches and plumbing or vent openings.
- Not enough insulation in the attic, so heat moves straight up to the roof deck.
- Poor attic ventilation, so warm air gets trapped under the roof instead of being replaced by cold outside air.
- Roof shape: valleys and low-slope sections collect more snow and meltwater.
Long term, the goal is to keep the roof deck cold and even from top to bottom, so snow melts slowly and evenly instead of melting up high and refreezing at the edge. Our roof inspection notes what we see in the attic and on the roof, so you know where the heat may be coming from. Blue Peaks doesn’t do insulation or air sealing. If the attic is the problem, a home energy auditor or an insulation contractor is the right call, and we’ll tell you so. On a roof replacement, we do look at the roof’s ventilation.
How to prevent ice dams before the next big snow
To make ice dams less likely:
- Clear your gutters and downspouts in dry weather before the snow starts, or have a professional do it. Don’t go up a ladder once there’s ice or snow. Clear gutters give meltwater somewhere to go, though the bigger factor is how much heat is reaching the roof.
- If you use a roof rake, use it from the ground only, after a heavy snow, to pull down the snow along the bottom few feet of the roof. Look up first and stay well away from power lines and the wires running to your house, since a metal or wet pole can carry current. Pull snow only: don’t chop or yank at ice stuck to the shingles. Stand out of the way of falling snow and ice. If you’re unsure, skip it and call a roofer.
- Ask about the roof edge. When we replace a shingle roof, ice and water shield, a self-adhering waterproof membrane, goes under the shingles in every valley and along the eaves. It’s a backup layer for water that backs up at the edge of the roof. It won’t stop ice dams from forming, so we also look at where the heat is coming from.
Can an ice dam leak wait until spring?
We’d rather you didn’t wait. Every melt-and-freeze cycle can push more water under the shingles and into the roof boards, insulation and drywall. Over time, wet materials can lead to rot and mold.
If your roof is already leaking from something other than ice, our post on what to do when your roof starts leaking walks through the first steps.
Roof repair in Denver and the Front Range: how we handle winter leak calls
Blue Peaks was founded in 2019 and is based in Littleton, and we hold Atlas PRO+ Silver and TAMKO Pro Platinum credentials. Our inspections come with photos and a written scope before any work begins. We handle urgent roof problems during business hours. If water is coming in, call us and we’ll get you on the schedule.
Not every leak means a new roof. Our job is to find out which kind you have and tell you the truth about it.
Seeing stains near your walls or ice along the roof edge? Call us at (303) 808-0687 or schedule a roof inspection. We’ll find the source, show you photos and give you a straight answer.