Foundation Repair Cost in Knoxville, TN

Knoxville foundation costs by type of repair

† Mudjacking / slab leveling: Sources disagree widely (>3x): polyurethane foam spot-lifts run well under $1,500, while full slab mudjacking with structural fill runs $4,500–$9,000. Range widened to cover both.

Older houses, older drainage

Much of Knoxville's housing stock is older, and age changes what goes wrong. Gutters sag and overflow, soil once graded away from the house settles flat or tips back toward it, and below-grade walls of concrete block or aging mortar start letting water through. Over decades, that water softens the soil at the footings and presses on basement and crawl-space walls.

So the first rows to look at are the water rows: drainage correction at $2,700–$11,800 and leak repair and waterproofing at $2,000–$11,800. If a block wall in a basement or deep crawl space has started to lean inward, bowing wall reinforcement ($3,900–$14,700) applies. Hairline cracks in an old wall that hasn't moved need only crack repair, at $200–$1,000 each.

Dolomite under the valleys

Knoxville sits in ridge-and-valley country, and parts of the bedrock under it are sinkhole-prone dolomite. Dolomite, like limestone, dissolves slowly along cracks. Soil above an opening can wash down into it until the surface sags or drops. On a house, that looks different from age-related settling: it is local, it can be quick, and the cracks keep growing.

When a void is the cause, the repair usually means piers ($1,000–$2,900 each) taken down to solid rock, sometimes with grout pumped into the opening, a cost this table leaves out. Full underpinning runs $4,400–$29,400. Rock depth can change sharply over short distances in dolomite, so ask how each quote handles piers that go deeper than planned.

Moderate clay across much of Knox County

The NRCS survey rates 0% of Knox County's soil very limited by shrink-swell, 32nd of 33 metros on this index, and names no high-shrink series of note. The other column tells more: 46% is rated somewhat limited. That is moderate valley clay. It swells and shrinks less than the heavy clays rated very limited elsewhere, but enough to keep an old crack working open a little each season.

Drought rarely drives the movement. Half or more of the county reached severe drought on 20 of 522 weekly maps, 32nd of 33, and the longest run lasted 11 weeks, October 2016 to December 2016. The most recent severe week came in February 2025.

How an older house fares under the wear exclusion

Standard homeowners policies exclude settling, earth movement, soil expansion and contraction, and wear and deterioration. On an older house, the wear exclusion often comes up first, since an insurer is likely to treat failing gutters, worn grading, and aging block walls as maintenance. A sinkhole drop is earth movement under the same standard wording. What a policy may cover is a sudden covered peril, such as a pipe that bursts and washes soil out from under the house. Read your own policy before filing.

Knoxville's prices next to Nashville and Charlotte

This page uses a 0.98 labor factor from statewide Tennessee construction wages, $1,495 a week, 4% below the national average. Nashville uses its own metro wages and lands at 1.02; Charlotte sits at 0.95. The middle of the Knoxville table is $4,900, close to $5,100 in Nashville. On an older house, the bigger swing comes from what the inspection turns up once walls and drains are opened.

Knoxville questions about older foundations and sinkholes

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