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Fix a gutter that overflows

We'll clean the gutter, clear the downspout, and tell you when to call a gutter professional.

Troubleshooting · Home plumbing
30–60 min
What you'll need
  • Gutter scoop or trowel
  • Hose
  • Ladder
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Steps

Goal: Clean the gutter and downspout, adjust slope, and restore flow.

  • Clean the gutter. Clear the downspout.
  • Check the gutter slope. Adjust hangers if needed.
  • Good: No more overflow. Bad: Gutter may be undersized—call a pro.

Clean gutter

Goal: Remove debris so water can flow.

  • Remove leaves and debris. Flush the downspout.
  • Good: Water flows. Bad: Check slope or call a gutter professional.

When to get help

Call a gutter professional if:

  • Cleaning and slope adjustment did not fix the overflow.
  • The gutter is undersized for the roof area.

Verification

  • No overflow during rain.
  • Water flows to the downspout and away from the foundation.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Clean gutter Remove debris from the gutter.
  2. Clear downspout Flush or snake the downspout.
  3. Check slope Verify the gutter slopes toward the downspout.
  4. Call gutter pro Overflow persists, gutter undersized—call a gutter professional.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Gutter cleanliness
  • Downspout flow
  • Slope
  • Steps already tried

Is the gutter or downspout clogged?

Clogged gutters and downspouts are the most common cause of overflow.

Clean the gutter. Flush the downspout with a hose. Clogged: cleaning should fix overflow. Clear: check slope and downspout placement. If the gutter is undersized, call a gutter professional.

Yes No

You can change your answer later.

Clog was the cause

Cleaning should fix the overflow. Clean gutters at least twice a year. Consider gutter guards to reduce debris.

Done

Does the gutter slope toward the downspout?

Gutters need slope so water flows. If level, water pools and overflows.

Check the slope. Adjust hangers if needed. Good slope: if overflow persists, the gutter may be undersized—call a gutter professional. Bad slope: adjust and test.

Yes No

You can change your answer later.

Call a gutter professional

Call a gutter professional if: cleaning and slope adjustment did not fix the overflow, or the gutter is undersized for the roof area. Adding downspouts or larger gutters may be needed.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a gutter overflow?
Common causes: clogged gutters or downspouts, insufficient slope toward the downspout, or gutters that are too small for the roof area. Cleaning is the first step.
Can I fix gutter overflow myself?
Yes. You can clean the gutter and downspout, adjust the slope, and add gutter guards. If the gutter is undersized, adding a downspout or larger gutters may need a gutter professional.
When should I call a gutter professional?
Call a gutter professional if: cleaning did not fix the overflow, the gutter is undersized for the roof area, or you need to add downspouts or replace the gutter system. Slope adjustment may need a pro.

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