By the Avsten Roofing & Construction team. Avsten has been roofing homes across Butler County and Greater Cincinnati since 2009, installs blown-in attic insulation as well as roofs, is a GAF and Owens Corning certified contractor, and holds a 4.8-star rating from 171 Google reviews.
Fighting ice dams or a ceiling stain you can’t explain? We’ll inspect the roof and the attic together, for free, and show you where the heat is escaping. Call 513-266-8289 (we answer 24/7) or request your free roof inspection.
Key takeaways
- An ice dam is a heat problem that shows up on the roof. Warm air leaking into the attic melts snow, which refreezes at the cold roof edge.
- Ohio’s freeze-thaw winters are prime ice dam weather. Research from UMass Amherst found dams can form with as little as 1–2 inches of snow on a poorly insulated roof.
- The lasting fix is in the attic: air sealing, insulation and soffit-to-ridge ventilation.
- Ice and water shield at the eaves is your backup. Ohio code requires it on new roofs.
- Never chip ice off your roof. Use a roof rake from the ground and calcium chloride, not rock salt.
If you’ve ever had a brown stain show up on a bedroom ceiling in February, right along the outside wall, there’s a good chance an ice dam put it there. Most people assume the roof is leaking. Usually the roof is doing its job, and the problem starts inside the house.
What is an ice dam?
An ice dam is a ridge of ice that builds up along the lower edge of the roof, right above the gutters. Here’s how it forms:
- Snow sits on the roof.
- Heat escaping from the house warms the roof deck above the living space, and the bottom layer of snow melts.
- The meltwater runs down under the snow until it reaches the overhang at the eaves, which sits outside the walls and stays as cold as the outdoor air.
- The water refreezes there, and the ridge of ice grows day after day.
- New meltwater pools behind the ice and backs up under the shingles.
Shingles are made to shed water running downhill, not to hold back standing water. Once it works its way under them, it finds nail holes and seams and drips into the attic, the insulation and finally your ceiling.
Why does Southwest Ohio get so many ice dams?
We don’t get Minnesota’s deep, steady cold. We get snow, then a 38-degree afternoon, then a hard freeze that night, over and over. Every cycle adds another layer to the dam. Building researchers at UMass Amherst note that ice dams can form with as little as 1 or 2 inches of snow when a roof is poorly insulated and air sealed and a few days below freezing follow.
How do you know if you have an ice dam problem?
| What you see | What it usually means | What to do |
|---|---|---|
| Thick icicles on one side of the house | Heat is escaping into that part of the attic | Have the attic checked before next winter |
| Ice building up on soffits or in gutters | Meltwater is refreezing at the eaves | Rake snow off the lower roof; watch inside for drips |
| Stains or peeling paint near outside walls | Water has already backed up under the shingles | Get the roof and attic inspected now |
| Damp or matted insulation near the eaves | Ongoing leaks are soaking the attic | Inspect soon; wet insulation stops working |
| Your roof melts bare before your neighbors’ | Your attic is losing heat | Check air sealing and insulation levels |
That last one is worth checking from the street the morning after the next snow. Bare patches over the living space mean heat is getting through.
What causes ice dams, and how do you stop them?
Montana State University Extension sums it up well: the root cause of most ice dams is heat leaving the home and melting snow on the roof, and the fix is almost always better insulation and air sealing in the attic. There are three parts to it.
1. Air sealing
Warm air leaks into the attic through every gap in the ceiling below it: recessed lights, the attic hatch, plumbing and vent pipes, wiring holes and the tops of interior walls. In older homes, like many in Hamilton’s Rossville and German Village neighborhoods, those gaps can add up to a hole the size of a dinner plate. Sealing them is the cheapest and most effective fix there is.
2. Insulation
Once the leaks are sealed, the attic needs enough insulation to keep heat in the house, where you’re paying for it. Many older homes around here have a few inches of settled, compressed insulation. Adding blown-in attic insulation is usually a one-day job.
3. Ventilation
A healthy attic stays close to the outdoor temperature in winter. That takes air moving in at the soffits and out at the ridge. UMass researchers call a soffit-to-ridge system the most effective way to keep roof sheathing cold. Soffit vents painted shut or buried under insulation are common, and so are bathroom fans that dump warm, wet air straight into the attic.
| Fix | What it does | Where it’s done |
|---|---|---|
| Air sealing | Stops warm air from reaching the roof deck | Attic floor and ceiling penetrations |
| Insulation | Keeps heat in the living space | Attic floor |
| Ventilation | Keeps the roof deck cold | Soffits and ridge |
| Ice and water shield | Stops leaks if water does back up | Roof deck at the eaves, under the shingles |
Does a new roof stop ice dams?
Not on its own, but it’s your last line of defense. Ice and water shield is a rubberized membrane that goes on the deck along the eaves before the shingles. It seals around every nail driven through it. As Fine Homebuilding explains, it’s really a leak barrier: it doesn’t stop ice from forming, it stops the water behind the ice from getting into the house.
In Ohio this isn’t optional. Local building departments note that every jurisdiction in Ohio has a history of ice damming, so the residential code calls for an ice barrier at the eaves. Every roof we install gets it. Many roofs put on 20 or 30 years ago have only a narrow strip or none at all.
If you’re replacing your roof and you’ve fought ice dams before, ask how far up the roof the membrane will run, especially over low-slope sections and valleys. Not sure your roof needs replacing yet? Here’s how to tell whether you need a roof repair or a replacement, and what changes when you replace a roof in winter.
What should you do if you have an ice dam right now?
Do:
- Use a roof rake from the ground to pull the bottom few feet of snow off the roof. Less snow means less meltwater feeding the dam.
- Lay calcium chloride ice melt across the dam to cut a channel so trapped water can drain. A nylon stocking filled with it works well.
- Catch any drips inside with towels or a bucket, and take photos for your records.
Don’t:
- Chip at the ice with a hammer, an ax or an ice pick. You will break shingles and gutters, and that damage often costs more to fix than the ice dam would have.
- Use rock salt. It’s hard on shingles, gutters and the plants and siding below.
- Climb onto an icy roof. No leak is worth that fall.
Heat cables have their place on a stubborn spot like a north-facing valley, but they treat the symptom, not the cause. If water is already coming in, call us at 513-266-8289. Someone answers day or night, and our roof leak repair team can stop the damage while you plan the long-term fix.
Frequently asked questions
Are icicles always a sign of an ice dam?
No. A few small icicles are a normal part of an Ohio winter. What we look for is thick icicles concentrated on one part of the house, ice building up on the roof edge or soffits, or any water showing up inside. Those point to heat escaping where the ice is forming.
Do clogged gutters cause ice dams?
Not by themselves. Ice dams form on the roof, right above the gutter, because of heat loss from the attic. Full gutters can make the ice build faster and add weight, so keep them clean, but cleaning them won’t stop ice dams if the attic is leaking heat.
Does homeowners insurance cover ice dam damage?
Many policies cover sudden water damage to ceilings, walls and insulation caused by an ice dam. They usually don’t pay to fix the underlying cause, like adding insulation or ventilation. Every policy is different, so call your agent, and photograph the damage before anything is cleaned up. Our insurance claim team can help document it.
Should I call a roofer or an insulation contractor?
Ideally someone who looks at both. The leak shows up on the roof, but the cause is usually in the attic. We inspect the roof and the attic in the same visit and install both roofing and blown-in insulation, so you get one diagnosis and one plan.
How long does it take to fix an ice dam problem?
The attic work, air sealing and adding blown-in insulation, is usually done in a day. Ventilation changes can add a little time. If the roof itself needs ice and water shield added, that happens during a roof replacement, which we usually finish in one day too.
Fix ice dams for good before next winter
The best time to solve ice dams is when there’s no snow on the roof. An inspection shows whether the problem is air leaks, thin insulation, blocked ventilation, missing ice and water shield, or a mix. Often the fix is in the attic, and it costs far less than a new roof.
- One inspection, roof and attic together, so you get one answer instead of two contractors pointing at each other
- Roofing and blown-in insulation from one company
- Ice and water shield on every roof we install
- Phones answered 24/7, so you’re not waiting until Monday with a drip in the ceiling
Rated 4.8 stars from 171 Google reviews and roofing Southwest Ohio since 2009.
Call 513-266-8289 or schedule your free roof inspection. We serve Hamilton, Fairfield, West Chester, Liberty Township and communities across Butler County and Greater Cincinnati.