Gutter Leaking at the Seams or Corners?

Quick answer: Most gutter leaks at a seam, a corner or an end cap come from sealant that the Las Vegas sun and heat have dried out and cracked. Most of them are a repair, not new gutters: the old sealant comes off, the joint is cleaned and resealed, and anything loose is fastened again. Call or text (725) 502-3114 for a free estimate.

Where is the gutter leaking?

Where the drip is tells you most of what is going on. A gutter has only a few places where two pieces meet:

A corner. Inside and outside corners are sealed and fastened. A drip at a corner, or a stain on the stucco under it, usually means the seal has cracked or the corner has worked loose.
An end cap. The cap that closes the end of a run is sealed the same way, and the sealant there breaks down the same way.
The downspout connection. Water leaves the gutter through an outlet into the downspout. A drip at the outlet, or at the first elbow below it, is a leak at that connection or an outlet so packed with dust that water backs up around it.
A seam in the middle of a run. A seamless gutter has no joints between the corners. If yours has a joint every 10 feet or so, it is a sectional gutter, and every one of those joints is a place to leak.

If the water comes down behind the gutter instead of dripping from a joint, that is a different problem. We cover it in why water runs behind your gutters.

Why do seams and corners leak in Las Vegas?

Sun and heat on the sealant. On a July afternoon, an aluminum gutter on a south- or west-facing fascia can get hotter than 150°F, and by the next morning it has cooled to 75°F or lower. That happens every day from May through October. In this climate the sealant at corners and end caps turns brittle and cracks within 5 to 8 years where the sun hits it, and the south and west sides go first.

Metal that moves every day. Aluminum grows when it heats and shrinks when it cools. A 40-foot run that heats past 150°F on a July afternoon and cools by 70 degrees overnight changes length by nearly half an inch. That movement pulls on every sealed joint, every screw and every hanger, and over the years a corner can work loose.

Long dry months, then a hard storm. Months can pass with no rain to show a leak. Then the monsoon, from June through September, can drop 1 to 2 inches of rain in under an hour. A crack that stayed dry all spring leaks in the first storm, often when nobody is outside to see it.

Water that sits on a joint. A joint that stays wet fails sooner. If a run has lost its pitch, or an outlet is packed with dust, water stands in the gutter after the rain and sits on the corner or end cap for days. A gutter should fall toward its downspout about 1/16 to 1/8 inch per foot.

Sprinklers and hard water. Las Vegas water is hard. A sprinkler or mister that hits a corner or a downspout every day keeps that joint wet far more often than rain would, and it leaves a white mineral crust behind.

Thin metal. Gutters made from thin .027-gauge or .025-gauge aluminum can warp in the heat, and a warped corner pulls its seal apart. We use .032-gauge aluminum as our standard.

What can I check from the ground?

You do not need to climb anything. Stay off the roof, and stay off the ladder in the rain.

Walk the house after a rain, or on a dry day after the sprinklers run. Look under each corner and end cap for drips, dark streaks on the stucco or a wet patch in the rock.
Test on a dry day. Aim a garden hose at the roof above the far end of a run, the end away from the downspout, and let it run for a few minutes. Watch the corners, the end caps and the downspout outlet for drips.
Look at where the drip comes from. A drip from the front or bottom of a joint is the joint. Water running down the wall behind the gutter is the roof edge or the way the gutter is hung.
Check again later. A corner still dripping long after the rain stopped means water is standing in the gutter at that spot.
Take a photo or a short video of the drip and text it to (725) 502-3114. It tells us more than a description.

A bead of caulk over a dirty, cracked joint rarely lasts. The old sealant has to come off and the joint has to be clean before a new seal will hold. A leaking end cap you can reach from a step ladder on flat ground is a fair do-it-yourself repair. Anything higher, or over tile, is not.

What does City Seamless do about it?

We look at the gutter from the roofline, not from the driveway. We check the sealant at the corners, end caps and outlets, the hangers, the pitch and whether the downspouts are flowing, so we fix the cause and not only the drip.

On a leaking joint we strip the old sealant, clean the joint and reseal it with commercial-grade sealant rated for desert sun. A corner or a section that has pulled loose gets fastened again, and a damaged downspout connection gets rebuilt. If water is standing in the run, the run gets re-hung to the right pitch so the new seal is not sitting in water. Cleaning and flushing are included when the repair needs them.

We repair all gutter types and brands, not only gutters we installed. When a section has to be replaced, we match the new piece to the color of the old gutter so the repair does not stand out from the ground. Our repair and re-hang work carries a 5-year workmanship guarantee.

Is it a repair or a new run?

It is a repair when the gutter itself is in good shape and the leak is at one or a few joints. Resealing a few corners and end caps on a seamless gutter is ordinary repair work. If a repair will give you five or more good years, we will tell you that and do the repair.

It is time for a new run when the joints are the whole problem:

A sectional gutter leaking at joint after joint along the run.
Thin aluminum that has warped, oil-canned or cracked.
Metal so corroded that new sealant will not hold.

A new City Seamless gutter is .032-gauge aluminum formed at your house in one piece for each run, so there are no joints along the run, only the corners and end caps. It carries a 30-year material warranty and a 5-year workmanship guarantee.

On price: in 2026, about seven of every ten of our small repair visits ran between $300 and $425, and larger repairs are priced by the job. New seamless aluminum gutter runs about $10 to $15 a foot, installed. Our gutter cost guide shows how we count the feet.

Frequently asked questions

Can a leaking gutter corner be fixed?

Usually, yes. The old sealant is stripped, the corner is cleaned and resealed, and it is fastened again if it has worked loose. Replacement is the right call when the gutter material itself has failed.

Why does my gutter seam keep leaking after I caulk it?

Usually because new caulk went over old, cracked sealant and dirt, or because water stands on that joint after every rain. The old sealant has to come off, the joint has to be clean, and the run has to drain so the joint is not sitting in water.

Do seamless gutters have seams?

Not along the run. A seamless gutter is formed at the house in one piece for each run, so the only joints are at the corners and the end caps, plus the outlets where the downspouts connect.

Do you fix leaks on gutters another company installed?

Yes. City Seamless repairs all gutter types and brands, not only systems we installed.

Is a leaking seam covered by your warranty?

On a gutter we installed, within the warranty period, yes. If a City Seamless gutter develops a leak or fails at a seam within the warranty period, we come back and fix it at no charge. Our repair and re-hang work carries a 5-year workmanship guarantee.

Related City Seamless resources

Want a number for your house? Request a free on-site estimate or Call or Text 725-502-3114.

About City Seamless Rain Gutter

Company: City Seamless Rain Gutter, family-owned in Las Vegas, with trade roots dating to 1976
Nevada Contractor Licenses: #0081882 and #0082656
Awards: Best of Las Vegas, Las Vegas Review-Journal, 2024 and 2025
Installations: 30,000+ homes installed
Standard Material: .032-gauge aluminum
Warranty: 30-year material warranty and a 5-year workmanship guarantee
Contact: Call or Text 725-502-3114 | cityseamless.com

Why Is My Gutter Leaking at the Seams or Corners?