Gutter leaks come from five places: a seam or corner joint, the downspout outlet, a hole or fastener in the gutter itself, the gap behind the gutter, and ice at the roof edge in winter. Where the water drips tells you which one. A drip under a joint means the sealant has failed. Water running down the fascia behind the gutter means rain is getting between the gutter and the house.
Find the leak first
| Where you see water | Likely source | Usual fix |
|---|---|---|
| A drip under the joint between two sections | Failed seam sealant | Strip, clean and reseal the joint |
| A drip at an inside or outside corner | Failed corner seal | Reseal or replace the corner piece |
| A drip at the end of a run | Loose or unsealed end cap | Refasten and reseal the cap |
| A drip where the downspout meets the gutter | Failed outlet seal | Reseal or reset the outlet |
| Water escaping from a downspout joint | A section fitted the wrong way, or loose | Refit so each piece sits inside the one below |
| Water running down the fascia behind the gutter | Water getting between the gutter and the roof edge | Tuck the gutter under the drip edge, or add a gutter apron |
| A drip from the middle of a run | A hole, rust or a loose fastener | Patch, reseal the fastener or replace the section |
| A leak only in winter | An ice dam or frozen outlet | Attic air sealing; clear the outlets |
Water pouring over the front of the gutter at a corner is overflow, not a leak. That usually comes from a roof valley, and a valley has its own fix.
To find the spot on a dry day, run a garden hose into the high end of the gutter and watch where the water comes out. A second person on the ground makes it quicker.
Why do gutter seams and corners leak?
Gutter seams and corners leak when the sealant in the joint fails. Sectional gutters are joined about every 10 feet, so a long run has several seams. Seamless gutters have none along the run, but every corner, end cap and outlet is still a sealed joint.
Temperature is what breaks the seal. Aluminum grows and shrinks with the weather, and Sioux Falls can swing from 20 below in January to the mid-90s in summer. Over that range, a 40-foot aluminum run changes length by close to three-quarters of an inch. Every season, that movement pulls at the sealant in each joint until it separates.
A lasting repair takes four steps: scrape out all the old sealant, clean and dry the metal, lay a gutter sealant along the inside of the joint, and keep it dry until it cures, usually about a day. A loose joint gets riveted before it is sealed. A corner or end cap that is bent or has failed more than once can be replaced on its own, without replacing the run. If water stands in the gutter after rain, fix the slope too. The gutter should fall at least 1/16 inch per foot toward each outlet.
Why is my gutter leaking at the downspout?
A gutter leaking where the downspout joins it has a failed outlet seal. The outlet is a short tube riveted and sealed into a hole in the bottom of the gutter, and its seal fails the same way a seam does. A clogged downspout makes it worse, because water backs up over the outlet and presses on the seal.
Leaks lower down come from the downspout’s own joints. Each piece should slide inside the piece below it, so water stays inside the pipe on the way down. A piece fitted the other way sends water out at every joint. Once it reaches the ground, where the water goes is its own question.
Why is water coming out behind my gutter?
Water running down the fascia while the gutter is half empty is not a gutter leak. It is water getting between the gutter and the house, usually because the gutter sits in front of the drip edge instead of behind it, the roof edge has no drip edge or gutter apron, the gutter has pulled away from the board, or the hanger straps are carrying water back. Left alone it rots the fascia and soffit and can reach the basement.
The guide to water running behind gutters covers how to tell it from overflow, each cause, what fixes it and why caulk does not.
Why is my gutter leaking in the middle of a run?
A leak away from any joint comes from the gutter itself: a hole, a rusted spot on a steel gutter, a crack from ice or a falling branch, or a loose fastener. Older gutters hung with long spikes through the front leak where each spike passes through, especially once the spike works loose.
A small hole can be sealed or patched. Holes in several places, rust along the run, or a split section mean that run needs replacing.
Why do my gutters leak in winter?
A leak that appears only in winter comes from ice, not a failed joint. Ice dams form when heat escaping the attic melts snow on the roof and the water refreezes at the cold eave. Meltwater then backs up under the shingles and can show up at the gutter, on the fascia or inside the house. Air sealing the attic and adding insulation prevent it. Our ice dam guide covers removal, heat cable and frozen downspouts.
Frozen outlets add to the problem. Ice in a downspout sends meltwater over or behind the gutter. Do not chip ice out of a gutter. It can crack shingles and bend or pull the gutter loose.
Can I fix a leaking gutter myself?
Resealing a seam, corner or end cap on a one-story house is a reasonable job for a careful homeowner with a steady ladder. Work on a dry day, strip the old sealant completely, clean the metal and seal the inside of the joint.
Call a pro when the gutter is on a second story, the gutter has pulled away from the fascia, the fascia is soft, or water is running behind the gutter. Those jobs mean rehanging the gutter or adding flashing at the roof edge.
How much does it cost to fix a leaking gutter?
Resealing gutter seams costs about $100 to $350, and a typical gutter repair costs about $195 to $625 in 2026. A second story, rotted fascia and replacement sections raise the price. A measured quote gives the local price.
Repair or replace?
Repair makes sense when the leak is at one or two joints and the rest of the gutter is sound. Replacement makes sense when joints keep failing after repair, rust or holes run along the gutter, or the gutter overflows because it is too small for the roof. The installation guide explains how gutters are sized for Sioux Falls rain.
Questions about leaking gutters
Why is my gutter leaking at the seam?
The sealant in the joint has failed, usually from years of the metal expanding and contracting. Strip the old sealant, clean the metal and reseal the inside of the joint.
Why is water dripping behind my gutter?
Water is getting between the gutter and the house. The gutter may be missing a drip edge or gutter apron above it, or it may have pulled away from the fascia.
Should a gutter be sealed from the inside or the outside?
From the inside. Sealant goes along the joint inside the gutter, on the side the water runs over.
Do seamless gutters leak?
Seamless gutters can leak at their corners, end caps and downspout outlets, which are sealed joints. The straight runs have no seams.
How much does it cost to fix a leaking gutter?
Resealing seams costs about $100 to $350, and a typical repair about $195 to $625 in 2026. Two-story homes and fascia damage cost more.
Get a quote
If the leak keeps coming back or water is getting behind the gutter, tell us about the job with a photo of where it drips, and a local gutter contractor will call, text or email to set up a visit. The quote is free.