Gutters overflowing? It's one of four things (and guards aren't always one)

Gutters that overflow aren't a cosmetic issue. The water they dump at the foundation is the leading cause of wet basements, rotted fascia, and ruined landscaping. The good news: it's almost always one of four causes, three of which you can diagnose standing in the yard during the next rain.

Watch it rain

Go outside during a steady rain and look at where the water is coming over.

| What you see | Cause | Fix | |---|---|---| | Overflow at one spot, usually near a downspout or a corner | Clog | Clean it out | | Water pooling and spilling mid-run, far from any downspout | Wrong pitch — the gutter is level or sloped backward | Re-hang the hangers | | Overflow everywhere during heavy rain only, fine in light rain | Downspouts too small or too few for the roof area | Add or upsize downspouts | | Gutter visibly sagging or pulled away from the house | Loose hangers, or the fascia board behind them has rotted | Re-fasten, or replace fascia | | Water running behind the gutter, down the fascia | No drip edge, or gutter hung too low | Install drip edge / apron flashing |

Fix 1: The clog (most of them)

Ladder, gloves, a bucket on a hook, and a garden hose. Scoop from the downspout outward. Then run the hose into the top of each downspout at full pressure — if it backs up, the clog is in the downspout, usually at the elbow at the top or the bottom. Disconnect the elbow and clear it, or blast it from below with the hose. A plumber's snake works for stubborn ones.

Single-story, stable ground, someone footing the ladder: DIY, $0. Two stories, steep grade, or you don't love ladders: a gutter cleaning service is $100–$250 and takes an hour. Twice a year — see the seasonal checklist.

Fix 2: Pitch

Gutters should fall about 1/4 inch for every 10 feet toward the downspout. Pour a bucket of water in the far end; it should run cleanly to the downspout without pooling. If it sits, the hangers have loosened or were installed level.

Re-pitching is tedious but not hard: snap a chalk line at the correct slope on the fascia, then loosen each hidden hanger (screwed through the back of the gutter into the fascia) and re-fasten to the line. New hangers are $1–$2 each; use 2-inch screws into solid wood, not the old holes. $20–$40 in parts, a couple of hours per run.

Fix 3: Not enough downspout

A single 2x3-inch downspout handles about 600 square feet of roof. A 3x4 handles about 1,200. If a long run with a big roof area above it has one small downspout at the end, it will overflow in every real storm no matter how clean it is. Add a second downspout at the other end ($40–$80 in parts, an afternoon), or replace the 2x3 with a 3x4 and enlarge the outlet hole in the gutter. This is the fix most homeowners never think of and the one that permanently stops "it overflows every time it pours."

Fix 4: Fascia rot — this is a different job

If the gutter is sagging and the screws won't bite, push a screwdriver into the fascia board behind it. If it's soft, the board is rotted and no amount of re-hanging will hold. That's a carpentry repair: remove the gutter section, cut out and replace the rotted fascia (and check the rafter tails behind it), prime and paint or wrap in aluminum, re-hang the gutter. $300–$1,200 for a handyman or gutter company depending on length and height, and it often reveals that the roof edge has been leaking for years. Do not ignore this one; rotted fascia leads to rotted rafters.

The honest take on gutter guards

Guards cut cleaning frequency; they don't eliminate it. Specifics:

• Micro-mesh guards ($10–$25/ft installed by a company, $3–$6/ft DIY) work best. They still need the mesh brushed off once a year, and in heavy rain water can sheet over the top on steep roofs.
• Foam inserts and brush guards ($1–$3/ft) clog inside and are worse than nothing after a couple of seasons. Skip them.
• Reverse-curve / "surface tension" guards work in moderate rain and overflow in downpours. Expensive, and they make cleaning harder when they do clog.

If you have a lot of trees overhead and hate ladders, micro-mesh is a legitimate buy. If you have a few trees, $200 a year for cleaning beats a $3,000 guard install. Any company that quotes guards without first fixing pitch and downspout sizing is selling you a lid for a bucket with a hole in it.

When to call a pro

• Two or more stories, steep yard, or you're not steady on a ladder. Falls from ladders cleaning gutters put a lot of homeowners in the ER every fall. $150 for a cleaning is cheap.
• Fascia is soft anywhere. Carpentry plus possible roof-edge repair — get it looked at before it spreads.
• Gutters are rusted through, seams leak at every joint, or they're the old spike-and-ferrule type pulling out of the wood. Seamless aluminum replacement runs $8–$15 per linear foot installed, roughly $1,200–$2,500 for an average house, and solves pitch and sizing at the same time.
• You've cleaned and re-pitched and it still overflows. Let a gutter company size the downspouts properly.

The Find a Pro page covers handymen and gutter contractors; for the fascia case, ask specifically for someone who does fascia and soffit, not just gutters.