A little water left in a gutter after rain is normal. A lot is not, and the line between the two is clearer than most people are told. If what is left is under a quarter inch deep and gone within a day or two, leave it alone. If it is deeper, stays longer, or sits along a whole run, the gutter is not falling toward its outlet the way it should.
How to check
Go up a day after a good rain, on a dry ladder, and look along the trough. Stand a tape measure in the deepest spot. Then look at where the water sits: one puddle, several, or the whole run. That pattern is most of the diagnosis.
| What you see | Verdict |
|---|---|
| A damp film, or a few puddles under a quarter inch | Normal. Nothing to do |
| A thin skim right at the downspout outlet | Usually the outlet lip. Minor |
| Puddles deeper than a quarter inch | Pitch problem at that spot |
| Water still there 48 hours after the rain | Pitch problem, a sag or a clog |
| A long stretch holding water end to end | The run is level or sloping the wrong way |
| Standing water in gutters installed this year | Workmanship. Call the installer |
Why some water is normal
No gutter drains perfectly. A seamless aluminum trough can have small waves along its length, a hanger can sit a fraction high, and the lip where a downspout outlet meets the gutter floor holds a skim of water by design. Installers on building forums will tell you most gutters have a flat spot or two, and they are right.
A quarter inch is the rule of thumb most of the trade works to. Below that, the water evaporates in a day or two and does no harm. Above it, you have a pitch problem worth fixing.
What causes a gutter to hold water
Not enough slope. A gutter should fall at least 1/16 inch per foot toward each outlet, about 5/8 inch over 10 feet. Some installers hang long runs nearly level because it looks cleaner from the street. It looks good and drains badly.
A low spot. One hanger has let go, or the fascia behind it has softened, and the gutter dips between two points. Water collects there and nowhere else. That is the start of a sag, and it gets worse each winter as the pooled water freezes.
A run sloping the wrong way. Settling and ice can leave a run level or tilted away from its outlet, so water collects at the far end. On a long run with an outlet at each end, the high point belongs in the middle. If it has drifted, one half drains and the other does not.
A clog you cannot see. Water standing everywhere, deepest near the downspout, often means the downspout itself is blocked below the outlet. A hose run into the gutter tells you in two minutes: if it fills and barely drains, clear the downspout first.
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Why it matters more here
Standing water in a gutter is where mosquitoes breed, and South Dakota has one of the highest per capita rates of West Nile virus in the country. More than 2,900 people in the state have been infected since 2002. The state health department lists making sure roof gutters drain properly among the steps it asks every homeowner to take, and the City of Sioux Falls asks property owners to cut standing water on their own lots to help its spraying program.
Winter is the other reason. Water that sits in a gutter in October freezes in November. Ice is heavy, it pulls on the hangers, and a trough that freezes full takes much longer to thaw than one that froze empty. Frozen gutters often start as gutters that never quite drained.
Standing water also keeps seams wet between storms, and a joint that never dries is the one that fails first.
Fixing it without new gutters
Repitching is repair work. The installer loosens the hangers along the run, resets the high end up or the outlet end down until the gutter falls at least 1/16 inch per foot, and refastens. On a low spot, it may be a single hanger replaced or added. If the fascia under that hanger is soft, the board has to be fixed first or the dip comes back.
Replacement only makes sense if the trough itself is creased or bent, or if the run is undersized and overflowing anyway. Most drainage problems are cheaper than that.
If the gutters are new
New gutters have no settling or loose hangers to blame. If a system installed this year holds more than a skim of water after rain, the pitch was set wrong, and that falls under the installer’s workmanship.
Before you call, photograph the water the day after a rain with a tape measure standing in it, note which run and how long it lasted, and find your warranty paperwork. Ask for the pitch to be reset to at least 1/16 inch per foot. A good installer will come back without an argument. It is also why a written workmanship warranty is worth insisting on before the job starts.
Questions about standing water in gutters
Is it normal to have standing water in gutters?
A thin film, or a few puddles under a quarter inch that dry within a day or two, is normal on most systems. Deeper puddles, water still there 48 hours after the rain, or one long flat stretch mean the pitch is off.
How much standing water in new gutters is acceptable?
The same quarter inch, gone within a day or two. New gutters have no settling or loose hangers to blame, so anything more is an installation issue and worth a call back to the installer.
Does standing water in gutters attract mosquitoes?
It can. South Dakota has one of the highest West Nile virus rates in the country, and the state health department specifically tells homeowners to make sure roof gutters drain properly.
Can gutters be repitched without replacing them?
Usually. Loosening the hangers, raising the high end or lowering the outlet end, and refastening is repair work. Replacement only makes sense if the trough itself is bent.
Why is water sitting right at the downspout?
Often the outlet itself. A drop outlet that sits slightly proud of the gutter floor leaves a lip that holds a skim of water. It is harmless in small amounts and fixable if it bothers you.
Is standing water covered by my gutter warranty?
If the installer’s workmanship warranty covers pitch and drainage, a new gutter that holds more than a skim of water is a fair claim. Photograph it after a rain, measure the depth, and call while you are inside the warranty period.
Get a quote
Tell us about the job, with a photo of the water the day after rain, and a local gutter contractor will call, text or email to set up a visit. The quote is free.
Related
- Sagging gutters, and what a rehang costs
- Why gutters overflow
- Gutter cleaning before the leaves and the freeze