Cause 1: the clog (most common under trees)
Packed needles and leaves — in the trough, at the downspout mouth, or inside the downspout itself — turn your gutter into a bathtub with no drain. Telltale sign: overflow at specific spots, plus water dribbling from the downspout when it should be surging.
The fix is clearing the blockage — and on wooded lots, guards so it doesn't rebuild by next month. We don't do standalone cleanings, but debris clearing is included in any repair or guard installation that requires it.
Cause 2 and 3: capacity and slope
If clean gutters still overflow, the system either can't hold the flow (undersized gutters or too few downspouts for your roof area) or can't move it (slope settled out of true, so water pools instead of traveling to the drops). Capacity fixes are added or upsized downspouts; slope fixes are re-hanging the run — both are permanent, engineered corrections rather than maintenance.
Gulf-Coast rain rates are the hidden factor: gutters sized to national defaults are sized for storms half as intense as ours.
Cause 4: the failure you can see
Sagging sections, separated seams, and gutters tipped away from the fascia spill water even in modest rain. That's not an overflow problem — it's a structural one, and it's the point where the repair-vs-replace question needs an honest, in-person answer.
Whatever the cause, don't diagnose it from the ground in a storm. A free walkthrough identifies which of the four you have — and the fix goes on an itemized written quote, not a guess.
The Takeaway
Overflow means clog, capacity, slope, or structural failure — in roughly that order of likelihood under trees. Each has a specific, permanent fix; none of them is 'live with it.'
Ready to act on this? Start with our gutter repair & replacement service — or go straight to a free on-site estimate.