Corner miters are built from several pieces, so one corner holds several seams, and debris collects there first. Wet debris sitting on aging sealant is a common cause of corner leaks.
Get My Free Estimate →Gutters leak at the seams and corners because the sealant in those joints ages, and the joints move as the metal expands and contracts with the weather. Eventually the seal lets go and water finds the gap.
What keeps a seam leaking is usually something else. Poor pitch, a sagging run or a clogged downspout leaves water standing on the joints instead of draining past them.
Buckshot repairs leaking gutters through our gutter repair service and installs seamless gutters, which remove most seams along a run. This guide shows where leaks start, how to find yours from the ground, and what a lasting fix involves.
Where gutter leaks start
Almost every gutter leak starts at a joint, not in a solid piece of metal. If you see drips, look first at the places where two pieces meet.
Seams between sections
Sectional gutters are built from pre-cut lengths joined along the run. Each joint relies on sealant and fasteners, and each one is a potential leak point.
Seams along the same run are usually the same age. When one starts leaking, the others are often not far behind.
Corner miters
Corners are a common trouble spot. A box-style corner miter is built from several pieces, so one corner can hold several seams in a small space.
Water also slows and changes direction at a corner, so leaves and grit settle there first. Wet debris sitting on several seams is a classic cause of a corner drip.
End caps
An end cap closes off the open end of a run. A neat drip at the very end of a gutter usually means its seal has failed.
Downspout outlets
The outlet is where water drops into the downspout, sealed around its edge at the lowest point of the trough. When the downspout backs up, water pools over that seal and works it loose.
Why gutter seams and corners fail
Seams fail from a mix of age, movement, water and weight. Wisconsin's freeze-thaw swings add to every one of them.
- Aging sealant: the sealant inside the joint hardens, shrinks and lets go of the metal over time
- Movement: the metal expands and contracts with temperature, working each joint back and forth
- Loose fasteners: when hangers pull loose, sections shift and the joints open
- Corrosion: standing water and packed debris wear at the joint from the inside
- Debris weight: a trough full of wet leaves and grit twists joints and pulls on hangers
- Poor pitch: a gutter without enough slope toward the outlet holds water over its seams and wears them out faster
That last cause is easy to miss. It is also why sealant dabbed over a drip often fails, because the gutter still holds water, twists away from the fascia or backs up from a blocked downspout.
Why a small gutter leak is worth fixing
A seam drip lands in the same spot every rain. It usually runs behind the gutter onto the fascia board, where the wood softens, the paint blisters and the hangers lose their grip.
Once the fascia softens, the gutter sags and holds more water, which wears out more seams. That is how one bad joint turns into a whole failing run, and our soffit and fascia service repairs the wood behind it.
Water escaping at a corner also lands near the foundation. Where it goes after it leaves the gutter matters too, as our guide to gutter drainage solutions explains.
In winter, water escaping a bad joint can freeze at the edge of the roof. The ice adds weight and pries the seam open further.
Not sure where your gutter leak is coming from? Our on-site gutter inspection is free, so you can find out whether it is a quick repair or a run that needs replacing.
Free on-site inspection · Family-owned since 1979How to spot the source from the ground
Watch the gutters from the yard during a steady rain, and the source usually shows itself. You do not need a ladder, and you should not climb one to chase a leak.
- Where the water appears: drips at a joint, corner or end point to a failed seal, while water pouring over the front edge points to a clog or poor pitch
- Water left standing: a waterline or dark stripe on the gutter after the rain stops means the run is not draining
- Streaks: dirty vertical streaks on fascia or siding below a joint show where water has been escaping
- The downspout: if little water comes out in a hard rain, the downspout is likely blocked
- The gutter line: a dip, a wave or a gap at the fascia means hangers are pulling loose, as our guide on gutters pulling away from the house explains
Take a phone photo of the drip if you can. It helps whoever inspects the gutter find the exact joint.
Where homeowner work ends
Watching from the yard and clearing the bottom of a downspout are reasonable to do yourself. Anything at gutter height is ladder work on a wet, flexible edge, and resealing or rehanging a run belongs with a crew.
How a proper gutter seam repair works
A lasting repair removes the old sealant, rebuilds the joint and fixes whatever kept it wet. New sealant over old sealant often separates again, because it bonds to a failing surface instead of clean metal.
- Clean the joint: old sealant and debris are removed down to clean metal.
- Realign and refasten: the sections are lined up and fastened so the joint stops moving.
- Reseal: the clean, dry joint is sealed with a gutter sealant made for metal.
- Correct the pitch: the run is adjusted to fall toward the outlet so water does not sit on the joint.
- Clear the drainage: outlets and downspouts are cleared so the gutter can empty.
Gutter repair professionals advise against clear silicone, roof tar and tape for seams. They do not bond well to weathered metal, and they make the next repair harder.
Our gutter repair team reseals seams and corners, refastens and repitches runs, and clears outlets. If water has already damaged the fascia, we repair that as well.
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We'll inspect it, document everything, and tell you honestly what you're looking at, even if the answer is patch it for now. No pressure.
When seamless gutters make more sense
Repair is the right call for one or two bad joints on otherwise sound gutters. Replacement makes more sense when several of these show up together.
- Several seams leaking along the same run
- Corrosion, pitting or dents in the gutter itself
- Hangers and fascia already damaged by long-term drips
- Pitch that cannot be corrected without rehanging the run
- Joints that were repaired before and failed again
Seamless gutters are formed in continuous lengths on site, so a straight run has no seams at all. That leaves only the corners, end caps and downspout outlets to seal.
Our comparison of seamless and sectional gutters covers the trade-offs, and our gutters page shows the full range of gutter work we do.
How to keep gutter seams from failing
Keep water moving and the gutters well supported, and the joints last much longer. Most early seam failures trace back to water that sat where it should have drained.
- Clean gutters at least in spring and fall, as our guide to cleaning gutters in Wisconsin explains
- Watch for dips that hold water after a rain
- Have loose hangers replaced while the fascia is still sound
- Fix a dripping joint in its first season, before it damages the wood behind it
Get your gutters checked
Buckshot Exteriors is family-owned, has served homeowners since 1979, and has offices in Madison, Wisconsin and Centerville, Iowa. We repair gutters and install seamless gutters, and our on-site inspection is free.
Call (608) 909-9109 to schedule your free inspection, or send us a message and we will set a time. If you would rather check first, watch your gutters during the next rain using the guide above.
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