The Collegedale soil
The national soil survey's Collegedale series was described from a site a mile and a half outside Collegedale. It is a deep, clayey soil weathered from limestone, sometimes with thin seams of shale, found on the uplands of limestone valleys. Water moves through it at a moderately slow rate, and bedrock is typically more than five feet down.
For a homeowner the practical points are these. The soil holds water after rain instead of passing it through, so drainage around the house does more of the work. And because the clay is thick, shallow footings bear on clay, not rock, and respond to how wet or dry that clay is.
Graded lots and newer houses
A subdivision lot is rarely level to begin with. The builder cuts the high side and fills the low side. If the fill was placed in thick layers or not compacted well, the part of the house standing on it settles in the first several years, while the part on cut ground does not. The classic signs are a crack in the brick near one corner, a garage slab that has dropped along one edge and a gap opening under the baseboard on the low side.
On a slab or a basement in one of these houses, an inspector will ask where the original ground level was. If you have the plot plan or grading plan from closing, have it ready.
Which office issues the permit
Collegedale is a city with its own permit office at City Hall, 4910 Swinyar Drive, (423) 396-3135. Ooltewah has no permit office of its own. Depending on where the lot sits, the permit comes from Collegedale, from Chattanooga or from Hamilton County Building Inspection, whose rule is that any repair to a structure needs a building permit. Your property tax record shows which government you are in, and the county office can confirm it from the address.
Worth saying on the phone
- The year the house was built and whether the builder is still in business
- Whether it stands on a slab, a crawl space or a basement
- Which side of the lot was filled, if you know
- Whether the movement showed up after a particular wet or dry season