Direct answer: Ice under a garage door usually means water is getting to the bottom edge, then freezing in place. Most of the time the real cause is a worn garage door bottom seal, packed snow against the outside face, or a slab that pitches water back toward the door.
Most likely: Start by clearing snow and slush away from both sides of the threshold, then look at the garage door bottom seal for flat spots, tears, or a gap at one corner when the door is closed.
This problem is usually more about water path than about the door itself. If the ice is a thin strip right under the seal, think air gap or meltwater sneaking under. If it is thicker at one corner, think slab slope, a twisted bottom edge, or a seal that no longer touches evenly. Reality check: a little frost at the threshold can be normal in deep cold, but a repeat ice ridge means water is finding the same path every time.
Don’t start with: Do not start by chipping hard at the ice with a shovel or prying on the bottom panel. That is a good way to tear the seal, bend the retainer, or dent the door.
A narrow frozen line runs under the bottom seal, and the door may crack loose when it opens.
Start here: Check for a flattened or hardened garage door bottom seal and for snow melt reaching the threshold from outside.
One bottom corner freezes down first, or you see a wedge-shaped patch of ice.
Start here: Look for a low corner in the slab, a crooked bottom retainer, or a seal that is shorter or torn at that end.
The problem shows up after plowing, shoveling, or daytime thaw followed by overnight freeze.
Start here: Focus on packed snow against the outside face of the door and meltwater running back under the seal.
You see damp concrete just inside the door before cold weather turns it into ice.
Start here: Treat it as a water-entry problem first and inspect the outside grade, threshold area, and bottom seal contact.
The bottom seal takes the abuse from concrete, grit, and cold. When it goes flat or brittle, meltwater slips under the low spots and freezes.
Quick check: With the door closed in daylight, look from inside for slivers of light under the bottom edge, especially at the corners.
Packed snow melts from sun, tire heat, or a warmer slab, then the water runs under the seal and refreezes overnight.
Quick check: Check whether the ice line matches the outside snow line or appears right after shoveling and plowing.
If the apron or interior slab is low at the door, even a decent seal can get overwhelmed by recurring runoff.
Quick check: After melt or rain, watch where a small amount of water naturally travels near the threshold.
A bent retainer, sagging section, or uneven door travel can leave one side touching and the other side hovering just enough to leak.
Quick check: Close the door and compare seal compression from left to right. One side will often look loose or show daylight.
You need the door free and the threshold visible before you can tell whether the issue is just frozen meltwater or a door alignment problem.
Next move: If the door opens normally once the ice is cleared, the main problem is usually recurring water at the threshold, not the opener. If the door still binds, lifts crooked, or feels unusually heavy, stop treating this as just an ice issue and inspect for track or spring trouble.
What to conclude: A door that frees up after ice removal points to water entry and freeze-back. A door that still moves badly may have a separate garage door problem.
A bad seal is the most common door-side cause, and you can usually confirm it without taking anything apart.
Next move: If you find an obvious gap or a brittle, damaged seal, you have a solid repair direction. If the seal looks healthy and contact is even, move on to where the water is coming from.
What to conclude: Even a small gap is enough for meltwater to wick under and freeze. A seal that still looks soft and even usually means the water path is outside the door.
Replacing a seal will not solve much if snow, runoff, or slab pitch keeps sending water to the same spot.
Next move: If you find snow contact or water pitching toward the opening, you have the source of the repeat freeze-up. If the outside area drains well and stays clear, the leak path is more likely at the seal or bottom edge of the door.
This is where you avoid buying the wrong part. A worn seal and a crooked bottom edge can look similar until you compare the contact pattern.
Next move: If the evidence points clearly to the seal, replace the seal and recheck contact. If it points to door alignment, stop before getting into spring-loaded hardware. If you cannot tell whether the gap is from the seal or the door sitting crooked, a garage door pro is the safer next step.
Once you know whether the problem is seal contact or repeat meltwater, the fix needs to address both the opening and the water path.
A good result: If the threshold stays dry through the next thaw-freeze cycle, you fixed the real cause.
If not: If ice still forms under a good seal with the area cleared, the slab or door alignment needs closer correction.
What to conclude: The lasting fix is the one that stops water from reaching the underside of the seal in the first place.
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Because closed is not the same as sealed. A small gap in the garage door bottom seal, especially at one corner, lets meltwater creep under and freeze. Outside snow piled against the door and a slab that pitches water inward make it worse.
Yes. A worn or hardened garage door bottom seal lets water reach the underside of the door. Overnight, that thin film turns into a glue line of ice and sticks the seal to the concrete.
Maybe, but check the floor and bottom edge first. One-corner ice often means that corner is lower, the retainer is bent, or the door is landing unevenly. Replace the seal when that corner of the seal is clearly damaged or not touching.
It can free the door in the moment, but it often leaves more water to refreeze into a larger sheet. Gentle mechanical removal and clearing the water source is the better long-term move.
Call a pro if the door is heavy, crooked, noisy in the tracks, or shows broken spring or cable problems. Bottom seal replacement is usually manageable. Track, cable, and spring issues are not the place to experiment.