Repair

How to Find a Gutter Leak Before You Call Anyone

By Houston Gutter Repair Co. · September 5, 2026 · 7 min read

A gutter leak is easy to find if you look while the water is running. Ten minutes with a garden hose on a dry day tells you more than a week of watching during storms — and September in Houston gives you plenty of dry mornings between the afternoon storms to do it.

What you'll need

• A garden hose that reaches the far end of each run
• A helper to move the hose or watch from the ground
• A flashlight, even in daylight, to look up under corners
• A phone to photograph each spot as you find it
• Chalk or painter's tape to mark leak points on the wall below

Pick a dry, calm day. Wet walls hide fresh drips, and wind blows the water around.

The hose test

Put the hose in the gutter at the end farthest from the downspout and let it run at about half pressure. Walk the run from the ground and watch for drips. Then move the hose to the other side of the house. Note where the water comes out and how — a steady drip at one point, a sheet over the front edge, or water running down the fascia behind the gutter. Those are three different problems.

Do it from the ground with a helper on the hose. You don't need to be on a ladder for this part, and on a two-story home you shouldn't be.

Drip at one point

Almost always a corner, end cap or seam. Look for a dark streak on the fascia or a wet spot on the ground directly under a corner. The sealant has failed. This is the one leak that's a reasonable DIY job on a single-story home: clean the joint with a wire brush and rubbing alcohol, let it dry, and apply a polyurethane gutter sealant (not silicone) inside the joint. Sealant needs the joint dry, which in Houston means picking a morning after two dry days, and it wants a few hours before the next storm. If the metal at the corner is corroded through, it needs a new corner piece — that's a repair call.

Sheet of water over the front edge

Not a leak — an overflow. The gutter is pitched wrong, the downspout is too small, or the run is undersized for the roof. We covered the diagnosis in why gutters overflow in Houston. Sealant won't fix this. A surprising number of people reseal every corner on the house, twice, before somebody tells them the downspout is the problem.

Water running down the fascia behind the gutter

Either the gutter has pulled away from the fascia — you'll see a gap at the top edge — or the roof has no drip edge and water is running back under the shingles. Look up from below with a flashlight. A gap means the hangers have let go; that's a re-hang. No drip edge is a roofing detail, cheap to add, and something any good gutter inspection should flag. If the fascia itself is stained dark and soft, the leak has been going on for years and the board is probably done — see fascia and soffit repair.

Downspout leaks: elbows and outlets

If water drips from a downspout elbow or seam when it's raining, the elbow has separated or a screw hole has opened up. Snap it back together and add a self-tapping screw; if it's split, replace the elbow ($10 part). This is the most common downspout repair Houston-area homes need and the easiest, and it matters more than it looks: a separated elbow dumps the entire run at the slab.

If the drip is at the top instead, where the downspout meets the gutter, the problem is the outlet — the hole cut in the gutter for the downspout — was sealed badly or the sealant has failed. Same fix as a corner: clean and reseal from inside the gutter. On older systems the outlet was cut with tin snips and never sealed at all; you'll see a ragged hole and a drip line straight down the back of the downspout.

Leaks that show up as something else

• A wet spot on the ceiling near an outside wall. Often water running behind the gutter into the soffit, not a roof leak. Check the fascia above it.
• Mud splashed up the brick in one spot. Overflow or a disconnected downspout above it.
• A trench in the mulch under the roofline. Overflow along that whole run, or no gutter there at all.
• Green algae on one section of siding. A slow corner drip that keeps that wall wet.

Leaks you can ignore for now, and ones you can't

A slow drip at a corner over a lawn is not urgent; plan a reseal in the next dry spell. A drip onto a wooden deck, a door threshold or the AC pad should be fixed sooner, because it soaks something that rots or rusts. Any leak that runs behind the gutter onto the fascia is the most urgent of all, since it's softening the wood that holds the gutter up. Rank what you found by where the water lands, not by how big the drip looks.

Leaks on two-story homes

On a two-story house, you can still do most of the hose test from the ground. Ask a helper to feed the hose from an upstairs window if one is near the run, or use a hose wand with a long reach from a short ladder at the low end. Watch with binoculars from across the yard. You're looking for the same three patterns, just from farther away.

What you shouldn't do is reseal a second-story corner from a tall ladder by yourself. A gutter on a 20-foot roof edge is a job for someone with standoffs and a second person. The test still pays off: you'll know which corner is leaking and can describe it clearly when you ask for a price.

Leaks after a new install

If a new gutter leaks, note where and when, and photograph it. Corner and outlet leaks in the first months are usually sealant that didn't fully bond, and they're a quick fix for the installer. Contact them promptly with the photos and a copy of your written terms. Don't try to fix it yourself first; that can confuse who is responsible.

Write it down

As you go, make a quick map: each side of the house, each corner, each downspout, and what you saw. Note the type of leak at each spot: drip, sheet, or behind the gutter. Photos with the tape marks in view make it easy to show someone later. A contractor who sees a clear list can usually give a firmer price, and you can compare two estimates against the same list.

Mistakes that make a leak worse

• Sealing over dirt. New sealant on a dirty, oxidized joint peels off within months.
• Using silicone. It doesn't bond well to old aluminum and goes hard in the sun.
• Sealing from the outside only. The bead belongs inside the gutter, where the water sits.
• Screwing through the bottom. Every new hole is a new leak.
• Leaning the ladder on the gutter. It dents the run and can change the pitch.

When to stop and call

• The gutter is sagging or pulling away (hangers, possibly fascia)
• The fascia is soft when you push on it (rot — nothing can be hung on it)
• More than two or three leak points on the house (the system is at end of life — repair or replace walks through that)
• It's a two-story roofline and you're not comfortable on a ladder that tall

A repair inspection from a local contractor should include the hose test from the ladder, a check of every corner and the fascia, and a written price. Most single-leak repairs are $150 to $250; the pricing page lists the rest.