Guttrz / Blog / Ice dams on Ohio roofs
Ice dams on Ohio roofs: causes and how to prevent them
Roofing by Guttrz: the owner inspects your roof himself, sends a photo report, and gives one flat written quote good for one year.
Ice dams on Ohio roofs form when heat leaking into the attic melts snow on the upper roof and the meltwater refreezes at the cold eave into a ridge that backs water up under the shingles. The fix is in the attic: seal air leaks, add insulation and balance soffit and ridge ventilation. Ice and water shield under the shingles at the eaves keeps backed-up water out of the house but does not stop the ice from forming, and gutters and gutter guards do not cause ice dams. Roofing by Guttrz in North Canton, Ohio inspects roofs free, including the eaves and attic, with a Good, Watch or Replace Soon photo report and one flat written quote good for one year.
Ice dams on Ohio roofs form when heat escaping from the house melts snow on the upper roof, the meltwater runs down to the cold overhang, and it freezes into a ridge at the eave. Water pooling behind that ridge backs up under the shingles and into the walls and ceilings. The cause is almost always the attic, not the gutters and not the shingles. This post covers why ice dams form on Northeast Ohio roofs, how to prevent them, what ice and water shield actually does, and when it is time to book a free roof inspection from Guttrz.
What causes ice dams on Ohio roofs?
Three things together: snow on the roof, a roof surface above freezing where the snow sits, and an eave below freezing. The Akron-Canton area gets about 47 inches of snow a season and spends November through March swinging above and below 32 F, so the snow and the cold eave are a given. The warm roof surface is the part you control, and it comes from the attic.
Attic heat loss
Warm air leaks into the attic through gaps around the attic hatch, recessed lights, bathroom fan housings, plumbing and wiring penetrations, and the tops of interior walls. That air warms the underside of the roof deck above freezing. Snow melts from the bottom even when the air outside is 20 F. The melt runs under the snow blanket to the eave, which hangs past the heated wall and stays cold, and freezes there.
Too little insulation
Insulation slows heat moving up through the ceiling. Most of Ohio sits in climate zone 5, where current energy codes call for about R-49 to R-60 in the attic, roughly 14 to 18 inches of blown fiberglass or cellulose. Thin or compressed insulation, or insulation pushed aside around the hatch and at the eaves, leaves warm spots on the deck that show up as bare streaks in the snow.
Poor ventilation
Ventilation flushes whatever heat does reach the attic back outside. Intake vents at the soffits pull cold air in low. A ridge vent lets warm air out high. When soffit vents are painted over, blocked by insulation or missing, or when there is no exhaust at the ridge, the attic holds heat and the deck stays warm.
Roof shape and shade
Valleys, dormers and low-slope sections collect more snow and drain slower. A north-facing eave in the shade of a maple stays colder than the rest of the roof. These spots dam first.
How do you prevent ice dams?
Keep the roof deck cold and the snow at the eave manageable. In order of how much they help:
- Seal the air leaks. Foam and caulk around every penetration in the attic floor, weatherstrip the hatch, and box in recessed lights that are not rated for insulation contact. This is the most effective step and the least expensive.
- Add insulation. Top up to the current target, with baffles at the eaves so the soffit vents stay open and air still moves.
- Balance the ventilation. Clear or add soffit intake and make sure there is ridge exhaust to match it. A common rule of thumb is 1 square foot of net free vent area for every 300 square feet of attic floor when intake and exhaust are balanced.
- Rake the first few feet of snow after a big storm, from the ground, with a roof rake. Less snow at the eave means less melt to freeze there. Never chip ice off shingles.
- Keep the gutters clear going into winter. A gutter full of leaves holds water and ice against the shingle edge. A late fall gutter cleaning in Canton lets the eave drain on thaw days.
Heat cable along the eave melts drain channels through an existing dam. It treats the symptom and does nothing about the attic.
What is ice and water shield?
Ice and water shield is a self-adhering rubberized asphalt membrane that sticks directly to the roof deck under the shingles and seals around every nail driven through it. It goes along the eaves, up the valleys, and around chimneys, skylights and vents, the places where water sits or runs hardest. Building code requires it at the eaves where the January mean temperature is 25 F or lower, which covers Northeast Ohio, running from the roof edge to at least 24 inches inside the exterior wall line. On most homes that means at least two courses of membrane above the gutter line.
Every Guttrz roof replacement includes ice and water shield at the eaves and valleys, synthetic underlayment over the rest of the deck, drip edge and a ridge vent. The full list is on the asphalt shingle roof replacement page.
What does ice and water shield do, and what does it not do?
It does keep the water that backs up behind an ice dam from reaching the deck and the house. If a dam forms and water pools 3 feet up the slope, the membrane under the shingles is what stops it.
It does not prevent ice dams. The ice still forms, still pries at the shingle edge and the gutter, and still soaks the fascia. It does not fix a warm attic, and a dam that climbs higher than the membrane runs will leak anyway. Think of it as the backup, with air sealing, insulation and ventilation as the fix.
Do gutters or gutter guards cause ice dams?
No. Ice dams form on roofs with no gutters at all. The ice you see in and over the gutter is the bottom of a dam that started on the shingles above, where the cold overhang met the melt from the warm deck. Guards do not change the deck temperature either. Our post on whether gutter guards cause ice dams goes through it in detail. What gutters can do is make the damage worse when they are packed with leaves, so clean them before the snow.
When should you call for a roof inspection?
Call if an ice dam has leaked into the house, if the same eave dams every winter, if shingles at the eave look lifted or cracked after a thaw, or if the fascia behind the gutter is stained or soft. These mean water has been getting under the roof edge, and they are on our list of signs you need a new roof in Northeast Ohio.
A Roofing by Guttrz roof inspection in Stark County is free. The owner checks the eaves, the valleys and the attic, looks for the staining and rusty nail tips that show past ice damage, and sends you a photo report with a Good / Watch / Replace Soon rating. If the roof is sound and the problem is the attic, the report says that. If it needs replacing, you get one flat written quote good for one year. Now booking spring 2027 roof replacements. Free roof inspections now. Book a free roof inspection in North Canton before the next thaw.
Common questions
Should I remove an ice dam myself?
Do not chip, hammer or pressure wash it, which cracks shingles and tears the gutter. From the ground, pull snow off the first few feet of roof with a roof rake so the dam stops growing. For an active leak, a sock filled with calcium chloride laid across the dam melts a drain channel in a few hours. Then fix the attic so it does not come back.
Why do I get ice dams when my neighbor does not?
Same snow, different attic. A house with sealed air leaks, deep insulation and balanced soffit and ridge vents keeps its roof deck cold, so the snow sits instead of melting. Roof shape matters too: valleys, dormers and shaded north eaves dam more. Two houses on the same street can behave very differently.
Do icicles mean I have an ice dam?
Not always, but big ones are a warning. A few small icicles on a sunny afternoon are normal melt. Thick icicles along a whole eave, ice climbing up over the shingles, or ice forming on a cloudy 20 degree day mean the roof deck is warm and a dam is building. Check the attic for warm spots and bare streaks in the roof snow.
Will a new roof stop ice dams?
Not by itself. A new roof with ice and water shield at the eaves and valleys keeps the backed-up water out of the house, and a ridge vent helps cool the deck, but the ice still forms if the attic is leaking heat. The replacement is the right time to add soffit intake and fix the insulation so the new roof stays dry.
Does a metal roof stop ice dams in Ohio?
Metal sheds snow faster, so dams are less common, but they still form where the attic is warm and the eave is cold, and sliding snow brings its own hazards. The attic fix is the same for any roof. Guttrz installs architectural asphalt shingles only, so a metal roof would come from another installer.
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Written by Christian Schaffner, owner of Guttrz. Updated November 7, 2026.
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