How To Fix A Gutter That’s Full Of Water And Overflowing

Need to know how to professionally fix gutters that are full of water and overflowing? Gutters can fill with water for many reasons. Clogs in the gutter system, improper pitching or slope of the gutters, and too large of a volume of water are the primary causes. In this article, I’ll teach you how to repair a gutter that is filling up with rain water and not draining properly.

Why You Should Repair Your Gutters If They Arent Draining Properly

Seamless rain gutters are an extremely important tool for diverting water away from your home. In fact, issues with rain gutters can lead to serious damage. Standing water levels cause seals to break down leading to rot near the home’s fascia line, moisture in your crawlspace, lawn erosion, overflowing, and many additional issues. I’ve even seen gutters completely fall off a home. It’s critical to repair rain gutters that are filling full of water to prevent these major water issues.

How To Fix Gutters That Are Full Of Water

Since there are many reasons why water may be holding in gutters we will walk through a superior gutter cleaning to help solve the root cause. This cleaning covers all steps that may be necessary to identify why your rain gutters are not draining.

1. Clean The Gutters By Hand From The Roof Or Ladder

Commonly, if a gutter is not draining properly there is most likely a blockage or clog in the gutter or downspout. If you are aware of issues your step should be to clean the gutters by hand from the roof or a ladder. You can also clean the gutters with a pressure washer or a leaf blower but we find using your hands works best.

2. Flushing Rain Gutters With A Water Hose

After cleaning the gutters by hand we will want to conduct a gutter flush. A flush includes taking high-pressure water and clearing the remaining leaf and shingle debris out of the gutters. We use a regular water hose with a hose nozzle set to the “Jet” position.


When flushing a gutter system it’s important to remove as much grain as possible EXCPECIALLY i the corners where you may have leaks and need to reseal.

3. Conducting A Gutter System Water Flow Test

A water flow test should only be conducted after the rain gutters are 100% clear of leaves, shingle grains, and dirt.

To conduct a water flow test we recommend switching your hose nozzle to the “Shower” mode. Aim the hose towards the high point or furthest away from the downspout side of the gutter. You will spray water directly at the roofline so water will trickle into the gutter naturally. Continue to let water flow into the gutter until water begins to move down the downspout.

Once water stops flowing out of the downspout you can observe how much water has or hasn’t stayed in the gutter.

“SAVE ZONE” Acceptable Amount Of Water In A Gutter

We flag any gutter that fills above 3/8″-1/2″ with water as misslope. Anything less is unavoidable and will allow water to dry out quickly enough to not cause issues. If a rain gutter is filling more than 1″ with water it’s alarming.

The reason gutter misslope can become alarming is simple. Debris build where water flows causing extreme amounts of weight in the gutter. This in return causes gutters to sag even more until the pitch of the gutter is unfixable.

Additional issues with water holding include quicker sealant breakdown. I’m no scientist but I find that gutters with misslope tend to have more leaks than gutters that are sloped properly.

4. Reslope/Repitch Gutters That Are Sloping Backwards

To fix any issues where you find water is holding in the gutter you will have to reinstall or adjust the pitch of the gutter.

Gutters don’t need to be sloped toward a downspout very much to drain properly. In fact, level gutters drain as water can only build so high before flowing out of the downspout.

When sloping a gutter it can be as simple as raising the high point by 1/4″ or dropping the low point by 1/4″. I’m not saying this is true for all gutters. In fact, every gutter will be different and some will need to be adjusted more than others.

Tools to use to help identify slope:

  1. Level
  2. The Water In The Gutter

5. Reseal The Corners & Endcaps Of Your Gutter

In many cases, gutters that have been holding water tend to also leak water from the corners. To solve issues with leaking gutter corners/gutter miters simply dry the gutter out completely. Use a leaf blower to blow all the additional water out of the gutter. Then, go to the corner or end cap you plan on resealing and finish drying the old seal out by dabbing it with a dry paper towel.

Once the areas are prepped and completely dry, use some Gerocel 2320 gutter sealant to reseal overtop of the old seals.


Your seamless rain gutters may be filling full of water for many reasons. Start with conducting a superior gutter cleaning and you will find the solution to your issue.

Follow the steps in order

  1. Clean the gutters by hand
  2. Flush the gutter system with a jet nozzle
  3. Conduct a water flow test with a shower nozzle
  4. Reslope the gutter if it is holding water
  5. Reseal all leaking corners and end caps

Frequently Asked Questions

What causes water to hold in a gutter?

There are two main reasons why water holds in a gutter.

  1. The most common reason is debris clogging the gutter or downspout. In this case, the gutter just needs to be cleaned.
  2. The second most common reason water doesn’t flow out of a gutter is due to improper pitching of the gutter. To solve this issue you will need to repair/re-slope the gutter.

How do you fix a gutter that is overflowing?

There are a few things you will need to do to repair a gutter that is overflowing. The simplest fix is to start with cleaning the gutter. If clearing the gutter of debris doesn’t work you will need to look into re-sloping the gutter. A third reason why a gutter may overflow with water includes it being the wrong side gutter or downspout for your roof size.

Is it bad for water to sit in a gutter?

More than 1/2″ of water sitting in a gutter is definitely not ideal. Stagnant water in gutters leads to leaking gutters, rotten fascia boards, mosquitos, and can eventually lead to the gutter falling off.

Why aren’t my gutters draining?

If your gutters aren’t draining they most likely need to be cleaned but could also not be pitched correctly. It’s recommended to start by cleaning your gutters and downspouts.

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