Karst, Slab Movement and Why Your Track Goes Out of Plumb

Greene County sits on limestone karst. The same geology that produced the caves and springs around the city is slowly moving the floor of your garage.

What karst does

Water works through limestone over time, creating voids. Ground above those voids settles - usually slowly, usually unevenly, and usually without anything dramatic happening. A garage slab that has dropped even a fraction of an inch at one corner is no longer a flat plane.

What that does to the door

The vertical track is anchored to the jamb and the jamb sits on the slab. Move the slab and the track is no longer plumb, so the rollers load against one side of the rail. The door gets noisier, the opener works harder, and the roller stems wear on one side.

The symptom people misread

A gap under the middle of a closed door, with both ends sealing correctly. Owners replace the seal, then replace it again. The seal is not the problem - the floor is no longer flat enough for any seal to bridge.

What can actually be done

Track can be re-shimmed and re-plumbed, and in many cases that restores normal operation without touching the slab. A threshold seal fitted to the floor can close a persistent low spot. Slab work itself is a foundation job rather than a door job, and worth knowing about before you spend more on doors.

Where it shows up most

The older parts of the south and south-east - Sequiota, Galloway, Brentwood - and anywhere the house has been standing over sixty years. Newer south-west subdivisions are not immune, but the settlement has had less time to accumulate.

Free estimate — no charge for the visit

Tell us what the door is doing and we will tell you what it normally means in Springfield. Every job is quoted in person and in writing before any work starts.

Call (417) 216-7189 Request a callback