Fall gutter and downspout checklist for Cincinnati basements

The big trees over Cincinnati's older streets drop their leaves over a few weeks in late October and November, and a surprising share of them end up in gutters. The timing is bad for basements. Gutters clog just before the long, soaking rains of late fall and winter, when the clay around your foundation is already wet and has little room left to absorb anything.

This checklist takes an afternoon, costs little or nothing, and removes the most common reason a basement that stayed dry all summer starts taking water in December.

Why a clogged gutter becomes a wet basement

Start with the arithmetic. One inch of rain on 1,000 square feet of roof is about 623 gallons of water. A house with a 1,500-square-foot roof footprint sends roughly 935 gallons toward its downspouts in a one-inch storm, and every one of those gallons is supposed to leave the house through a few openings the size of your fist.

When the gutter above a downspout is packed with leaves, that water sheets over the edge and lands in a line along the foundation, right where the soil was dug out and backfilled when the house was built. Backfill is looser than the undisturbed clay beyond it, so it soaks up water fast and holds it against the wall. That is how one overflowing corner produces a wet stripe on the basement wall directly below it.

If your basement leaks in one corner after rain, look straight up at the gutter above that corner before you look at anything else.

Step 1: Clean after the leaves are down, then flush

Clean once most of the trees near the house are bare. Some oaks hold their leaves well into winter, so a lot with big oaks may need a second pass. After scooping, run a hose at the far end of each gutter run and watch three things:

• Water should reach the downspout without pooling. Standing water in a run means it has lost its pitch or a hanger has pulled loose.
• Seams and end caps should stay dry underneath. A drip at a seam puts water right on the foundation line.
• The downspout outlet should run as hard as the hose. A weak trickle means a clog in an elbow.

For second-story gutters or a steep roof, paying someone to clean them is cheap compared with a fall from a ladder.

Step 2: Find out where each downspout actually goes

In many older Cincinnati neighborhoods, downspouts never empty onto the lawn. They drop into a pipe at the base of the wall that connects underground to the building sewer. The Metropolitan Sewer District notes that in many parts of the city downspouts are tied directly into the building sewer, and it lists frequent gutter cleaning as a way to keep debris out of that line.

That buried connection is easy to forget and easy to break. Roots crack it, leaves pack it, and a settled joint can leak straight into the soil beside your footer. To test it, run a hose into the top of the downspout for five minutes. If water backs up and spills at ground level, or the soil around the base turns to mush, the underground run is blocked or broken.

Before you cut a downspout loose from the sewer and turn it onto the yard, check with your city or MSD. A disconnection changes where a lot of water goes, and a careless one can put it on a neighbor, a sidewalk, or your own foundation.

For downspouts that already discharge at the surface:

• Extend them so the water lands well past the backfill. The Residential Code of Ohio asks new homes to drop 6 inches of grade in the first 10 feet from the wall, which is a good picture of the zone you want roof water to clear.
• Aim extensions at ground that falls away from the house, never toward a window well or a patio that drains back.
• On a hillside lot, do not empty roof water onto the slope. Ohio's Geological Survey lists downspout water discharged onto slopes among the practices that set up slope failures in landslide country like ours.

Step 3: Check the grade hiding under the mulch

Soil next to a house keeps settling for years, and mulch beds, edging, and raised borders quietly trap water against the wall. Pull the mulch back in a few spots along each wall and look at the soil itself. Lay a 10-foot straight board out from the foundation with a level on it. If the far end is not clearly lower than the end touching the house, water is not being pushed away.

Walks and patios matter too. The same section of the Ohio code asks hard surfaces within 10 feet of the foundation to slope at least 2 percent away from the building, which is about a quarter inch per foot. A patio that has settled back toward the house can pour water onto the wall in every storm.

Step 4: Clear the drains between you and the street

• Street inlets. The City of Cincinnati's Stormwater Management Utility maintains about 30,500 inlet and intake structures. Rake leaves away from the curb, not into it, and report a clogged or damaged inlet to the utility at (513) 591-5050.
• Window wells. A few inches of wet leaves can seal the drain at the bottom of a well, and then it fills like a bucket. Scoop them out, and see our answer on window wells that flood if yours already has.
• Sump and yard outlets. Pop-up emitters and yard drains vanish under leaves. If the lid of an emitter cannot lift, the water your sump pumps out has nowhere to go.

Step 5: Watch the first hard rain from the basement

The first soaking storm after cleanup is your test. Go downstairs with a flashlight while it is still raining and look along the base of every wall, around the floor drain, and at any crack. If a corner that used to leak now stays dry, the gutter was the problem. If water still appears where the floor meets the wall along more than one wall, it is coming from saturated soil at footer depth, and gutters alone will not stop it. That pattern is what interior drainage is built for, and our answer on whether gutters and grading are enough explains the difference.

National cost guides put new gutters and downspouts at roughly $3 to $30 per linear foot and regrading around a house at roughly $500 to $3,000, so the outside fixes are almost always the cheapest place to start.

What to do next

Work through the list this weekend, then write down what the basement does in the next real rain. If you still see water, walk through the basement water diagnosis to put a name on the pattern, then call or text us with what you found. We will tell you plainly whether you are looking at a gutter problem or a groundwater problem.