LEE'S SUMMIT

Lee’s Summit spread outward through the seventies, eighties and nineties and then kept going, so most of what we see here is a full basement under a house that is somewhere between twenty and fifty years old. The ground rolls, which means a lot of these lots were cut into terraces before the walls went in.

Jackson County clay holds water all through a wet spring and then gives it up in a dry August, and a basement wall feels that as pressure from one side that comes and goes with the season. A horizontal crack partway up a poured wall, or a stair step running through block, is the shape that turns up most often.

We have worked more than 150 foundation and waterproofing jobs in Lee’s Summit that are still on our books, and plenty more before the records start. On a soil this variable, that volume is what lets us say which of the city’s three soils we think you are on before we arrive.

What the ground under Lee’s Summit is actually doing

Most of Lee’s Summit sits on Sharpsburg and Arisburg, both moderate movers with linear extensibility around 4.3 to 5.1. That is the comfortable middle of the range and it is why a lot of Lee’s Summit houses never give any trouble at all.

The complication is Snead, which covers a further eighth of the city and is a different animal — roughly 43% clay and an extensibility of 7.5. Two houses on the same street can sit on soils that behave quite differently after the same dry spell, which is why we would rather look than guess when someone calls about a crack here.