The clay problem
Missouri clay swells when wet and shrinks when dry. That cycle puts lateral pressure on a foundation wall and then relieves it, over and over.
Horizontal cracks partway up a basement wall are the classic sign of lateral soil pressure. Vertical and stair-step cracks are more often settlement, which the same water cycle drives from underneath.
The backfill zone
When a foundation was dug, the soil put back against it never compacts to the density of undisturbed ground. It stays looser and more permeable forever.
Water discharged at the wall goes preferentially into that zone and down to the footing. That's the path a downspout extension is designed to bypass.
What to look for
A trench worn into the mulch under a downspout. Efflorescence — the white powdery deposit — on the inside of the basement wall. Damp spots that appear a day after a storm. Settled sidewalk or patio next to the house.
A doorframe out of square upstairs on the same corner as a wet basement spot is worth taking seriously.
The fixes, cheapest first
Extensions. Six feet minimum, ten on flat ground. Cheap and it solves a surprising share of complaints.
Grade correction so the ground falls away from the house for the first ten feet. Six inches of drop over that distance is the working target.
Buried solid PVC out to daylight or a pop-up emitter. This is the real answer on flat lots and hillside sites.
Questions people ask
Can gutters really cause foundation problems?
Yes, and it's one of the most common causes in this region. Clay soil plus water at the wall is the mechanism.
How far should water discharge from the foundation?
Six feet minimum, ten on a flat lot.
Will fixing my gutters fix a wet basement?
Frequently, and it's always the first thing to rule out. It's far cheaper than interior waterproofing and it addresses the source.
Is a splash block enough?
Rarely. It stops erosion right at the elbow and leaves the water in the backfill zone.
Free estimate
We measure, we look at the fascia, and you get a number in writing.
Talk to a real St. Louis gutter company
Third generation, family-run since 1947. Somebody picks up, day or night.