Gutters overflowing: 4 root causes (it's not always leaves)

What to do, in order

1. Watch during rain: overflow at one spot = local clog; overflow along the whole run = capacity or pitch problem.
2. Clean thoroughly (gloves, scoop, hose from the far end toward the downspout), then verify flow at the outlet with the hose.
3. Check pitch: gutters should drop ¼ inch per 10 feet toward downspouts. Use a level app on the gutter lip.
4. Count downspouts: one per 30–40 feet of gutter max. A single 2×3 downspout drains ~600 sq ft of roof — half a typical house.
5. Check underground outlets: downspouts buried to nowhere back up exactly like clogs. Run hose water through and watch the exit.
6. If still overflowing clean and correctly pitched: upgrade to 6-inch K-style gutters and 3×4 downspouts — often the real fix on steep roofs.

Red flags — stop and call a pro

• Water in the basement or crawlspace during normal rain — grade and gutter audit now
• Soil pulling away from the foundation or new stair-step cracks in brick — water is undermining the footing
• Gutter pulling away from fascia — fastener failure, re-hang before the next storm
• Soggy flowerbed against the house that never dries

Prevention

Clean gutters spring and fall (more if over trees), add leaf guards on the top third of runs only (full covers often clog worse), and extend downspouts 4–6 feet from the wall.

This guide is maintained by the ee.ltd editorial team — reviewed for 2026. Browse all home repair guides or compare roofing costs.

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What this repair typically costs

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