LIBERTY

Liberty has been here since 1822 and the range of foundations reflects that. Around the square there are houses on stone and on early block, and out past them are subdivisions built in the last forty years on ground that had to be graded first.

North of the river the limestone comes up close to the surface in places, so a basement can sit partly on rock and partly on clay. That is the situation that causes trouble, because only one of those two things moves.

Our records hold more than 75 jobs in Liberty, a good share of them on the older stone and block basements the city is full of. That is a particular kind of experience and it does not transfer well from newer suburbs.

What the ground under Liberty is actually doing

Under Liberty the survey finds Sharpsburg first, then Knox, then Sibley — a loess and glacial-till mix with linear extensibility between 3.2 and 4.8. Moderate to low. Around 27 to 33% clay.

Liberty’s older housing stock matters more here than the soil does. A stone or block basement built before these subdivisions existed is holding back the same modest soil pressure a modern poured wall would shrug off, but it is doing it with mortar that has had a century of freeze and thaw. The wall is usually the weak part of that pairing, not the ground.