Ice in gutters forms when meltwater from a warm roof refreezes at the cold eave, or when water standing in a poorly pitched or clogged gutter freezes in place. The weight bends hangers, pulls gutters off the fascia and can push water back under the roof edge. NRCA and Building Science Corporation agree that the lasting fix is to stop attic heat from melting the snow, not to heat the gutter. This page is general information.
On this page: Signs · Causes · Ground check · Fixes · Basis · When to call
Signs of gutter ice trouble
- Gutters packed solid with ice, or ice built up over the front lip.
- Long icicles along one part of the roof but not others.
- Gutters sagging, tilted outward or pulled away from the fascia after winter.
- Bent or broken hangers; split seams and end caps.
- Water stains on the soffit, fascia or interior ceiling near an outside wall.
What puts ice in the gutter
| Cause | Clue |
|---|---|
| Attic heat melting snow (ice dam process) | Icicles and ice over warm rooms, recessed lights or a poorly sealed attic hatch |
| Gutter pitched wrong or sagging | Ice thickest at a low spot mid-run |
| Downspout clogged or frozen | Ice fills the gutter next to the downspout |
| North-facing or shaded eave | Ice lingers on one side long after the rest has melted |
| Valley dumping into one spot | Ice mound under an inside corner |
The ice dam process itself is covered in our guide to ice dams.
What to check from the ground
- After a snow, look along the roof for bare stripes or early melting. Those spots sit over heat leaks.
- Note where icicles form and whether they come back after each storm.
- When the ice melts, sight down each gutter for sags and check that hangers are still tight to the fascia.
- Look at downspout outlets. A downspout that freezes shut backs ice up the gutter.
- Inside, look at ceilings and walls along exterior walls for stains after a thaw.
Stay off ladders on ice. Do not chip or pry ice from gutters or shingles.
The correct fix, and the wrong ones
| Fix | When it fits |
|---|---|
| Air seal and insulate the attic floor; make sure exhaust fans vent outside | Icicles and ice over living space; bare stripes on the roof. |
| Re-pitch gutters and add hangers | Ice forms at low spots or the gutter sags. |
| Clear and reroute downspouts away from shaded, north sides where practical | Downspouts freeze shut. |
| Replace bent runs and broken hangers | Gutters pulled loose or deformed after winter. |
| Install ice barrier membrane at the eaves at the next reroof | Water has backed up under the shingles. |
Wrong fixes: heat cable as the only fix for a warm attic, chipping ice, salt pucks thrown on the roof, or replacing gutters without fixing the attic heat that fills them with ice.
What roofing and building science guidance says
- NRCA, Ice dam busting (2012). Removing gutters is the most effective step in ice dam areas. Where they stay, they should slope to drain, be cleared before winter and use open or corrugated downspouts, kept off the north side where practical. NRCA advises against heat cables and says the cause is heat from below the deck.
- Building Science Corporation, BSI-046 Dam Ice Dam. Ice dams need snow, a roof deck above freezing and a cold edge. The fix is an airtight ceiling, heavy insulation above it and ventilation under the deck; heat cables throw energy at the problem.
- Englert gutter guidance. About 1/4 inch of slope per 10 feet toward the downspout and hangers no more than 18 to 24 inches apart. Englert also suggests heating elements in freeze-prone areas, which conflicts with NRCA and BSC.
See gutters pulling away from the house for the hanger and fascia damage ice leaves behind, and overflowing gutters for summer drainage problems.
When to call
Call when ice is leaking into the house, when gutters have pulled loose, or when the same heavy icicles return every storm. We install gutters, including metal gutters in the Denver area, and we look at attic ventilation during every roof inspection. Our Colorado Springs gutter page explains the gutter types we install, and the exterior problems guide lists related issues.
Book a winter gutter and roof check
Integrity Roofing and Painting is veteran-owned and family-run since 1990, an Owens Corning Platinum Preferred contractor with 650+ Google reviews. Colorado Springs area: call (719) 488-2800 or book a free inspection. Denver metro: call (303) 209-0152 or book a free Denver inspection. Austin: call (512) 610-5897 or book a free Austin inspection. We reply the same business day.
Sources: NRCA Professional Roofing, Ice dam busting (2012); Joseph Lstiburek, BSI-046 Dam Ice Dam (Building Science Corporation); Englert, Avoid these mistakes when installing gutters.
