Gutters do not cause ice dams: heat leaking from the house warms the upper roof, the snow melts, and the water refreezes at the cold eave (University of Minnesota Extension). The lasting fix is attic air sealing and insulation, while strong, well-hung gutters and clear downspouts limit the damage when ice does build up.
How an ice dam forms
University of Minnesota Extension explains it this way: an ice dam needs the higher part of the roof surface to be above 32 degrees while the lower edge stays below 32. Snow on the warm upper roof melts, runs down, and freezes again when it reaches the cold eave over the overhang. Day after day the ridge of ice grows, and meltwater backs up behind it, under the shingles and into ceilings and walls. The root problem is uneven roof temperature, and the heat behind it comes from inside the house.
Why Central Iowa homes get them
Des Moines averages 36.5 inches of snow a season under the National Weather Service's 1991 to 2020 normals, and the record for a single day is 19.8 inches on January 1, 1942. Polk County sits in building climate zone 5A, per OpenEI county climate data. Weeks of snow cover on the roof, combined with heat escaping into the attic, is the setup for ice dams, especially on homes with warm attics or complicated roof lines.
Fixing the cause: the attic
University of Minnesota Extension says the first long-term step is to make the ceiling airtight so warm, moist air cannot flow from the house into the attic, and the second is to add insulation. ENERGY STAR recommends R60 for an uninsulated attic in zone 5, or R49 when adding to 3 to 4 inches of existing insulation. Flow Right does not do insulation or air sealing, so that work belongs with an insulation or energy contractor. It is still the step that stops ice dams from forming.
What to do when a dam has formed
University of Minnesota Extension says the immediate step is to remove snow from the roof. A roof rake can do that from the ground, though Extension warns it may damage roofing. Making channels through the dam with tap water on a warm day lets trapped water drain off. This Old House advises hiring a professional for removal unless you have the training and safety gear. Climbing an icy ladder to chip at a frozen gutter is how people get hurt and gutters get torn off.
What gutters and guards can and cannot do
No gutter or guard stops an ice dam. This Old House says gutter guards do not reliably prevent them, and notes that piled snow can cause gutters to sag or pull away. Gutter Topper's own published terms exclude damage from ice dams. Heat cable is a separate product that we do not install. What gutters can do is survive the load and keep meltwater moving once it reaches them. That means hangers screwed into solid fascia, the right thickness of metal, and downspouts that are not frozen shut or blocked.
Gutter details that help in winter
Angi says contractors use 0.027 or 0.032 aluminum and warns that thin 0.019 aluminum is prone to warping or even collapsing under accumulated snow. We hang seamless gutters on hidden hangers driven into sound fascia, keep outlets clear, and size downspouts so meltwater can leave in a thaw. University of Minnesota Extension says extensions should carry water at least 4 feet from the wall. Downspout hinges and flip-ups make that easy to keep clear around snow and mowing. Our gutter repair page covers the fixes.
A spring check after an ice-dam winter
When the snow is gone, walk the house. Look for gutters that dip between hangers, bent outside corners, end caps pulled loose, and downspouts split from freezing. Check the fascia board and soffit for stains or soft spots where water got behind the gutter. Inside, look for ceiling stains along exterior walls. Bent gutters can often be rehung or replaced in sections. If several runs are damaged, our repair or replacement guide helps you decide which way to go.
Common Questions
Do gutters cause ice dams on Iowa homes?
No. University of Minnesota Extension says ice dams form when heat from the house warms the upper roof above 32 degrees while the eave stays below freezing. Clogged or sagging gutters can make the backup worse, but the cause is heat loss into the attic.
Should I take my gutters off to stop ice dams?
The sources we rely on do not support removing gutters. They point to attic air sealing and insulation as the fix. Without gutters, meltwater and rain drop straight along the foundation, and University of Minnesota Extension says missing gutters send water toward the foundation perimeter.
Is it safe to break up an ice dam myself?
University of Minnesota Extension suggests clearing roof snow and making channels through the dam with tap water on a warm day, and warns that roof rakes may damage roofing. This Old House advises hiring a professional unless you have the training and safety gear. Hammering ice off can also break the gutter.
What to Do Next
If last winter left your gutters bent or pulling loose, call or text Luke at (515) 901-3646 or send our estimate form. We will rehang or replace what is damaged and set your downspouts up to drain in a thaw.
See our gutter repair service or call or text (515) 901-3646.
Sources
- University of Minnesota Extension: Dealing With and Preventing Ice Dams
- This Old House: Best Gutter Guards for Snow (2026)
- ENERGY STAR: Recommended Home Insulation R-Values
- OpenEI: Polk County, Iowa climate zone
- National Weather Service Des Moines: Des Moines Climate Extremes and Normals (1991-2020)
- Angi: Gutter Thickness Guide (2026)
- University of Minnesota Extension: Moisture in Basements, Causes and Solutions
- Gutter Topper: Owner terms and care instructions (PDF)
Cost figures above are published market ranges from these sources, not Flow Right Construction prices. Your price comes from a free estimate.