Knoxville

Helical piles in Knoxville, Tennessee

Much of Tennessee sits on soluble rock. According to the U.S. Geological Survey, carbonate rocks underlie most of Middle Tennessee and large areas of East Tennessee, producing sinkholes and irregular bedrock surfaces. Clay-rich residual soils over limestone can be soft in some spots and pinned on rock pinnacles in others, which leads to uneven settlement.

Frost is modest, and Knoxville uses a 12-inch figure similar to Nashville's, where the code requires exterior footings at least 12 inches below undisturbed ground. Helical piles suit the sloped, wooded lots common around Knoxville, and in karst terrain the engineer may want borings before choosing pile locations.

Helical pile companies serving Knoxville

Two companies are based in Knoxville.

• Ram Jack Eastern Tennessee: a listed Ram Jack contractor near Knoxville; ask which foundation systems it installs before booking.
• Master Services: repairs foundations and crawl spaces and waterproofs basements across East Tennessee; ask which foundation systems it installs before booking.

Costs and what to ask

National figures from HomeGuide show installed helical piers at about $2,000 to $4,000 apiece. Tennessee projects vary with depth to rock, the number of piers, and site access. Read our helical pier cost guide for what a quote should include.

Questions to put to any installer:

• Is the pile layout stamped by an engineer over karst bedrock?
• Will the crew log torque at every pile and hand over the log at the end?
• What are the shaft size and helix configuration, and how is the steel protected in clay soil?
• Is a permit required through the City of Knoxville or Knox County, and who handles it? What does the warranty include in writing?

For the wider picture, see our page on Tennessee helical pile installers.