Retaining walls for Kingsport's ridges and river bluffs

How it works

1. Call or send a request

   Give us the address and describe what the wall or bank is doing.

2. We connect you

   We send it to an independent retaining wall contractor that covers your part of Sullivan or Hawkins County.

3. They call you back

   The contractor comes out, measures and quotes you directly.

Who uses this service?

Homeowners, landlords and small commercial owners in Kingsport, Colonial Heights, Church Hill, Blountville and the hollows and ridge roads around them. Kingsport counted 55,442 people in the 2020 census and spreads across two counties, Sullivan and Hawkins, where the North and South Forks of the Holston River come together. The city sits at about 1,211 feet, but the ground climbs fast in every direction, so a lot of houses here were set on a cut bank, a filled lot or a slope that ends at a creek.

Why is the ground around Kingsport hard on walls?

Kingsport lends its name to a layer of rock. Geologists call one unit of the Knox Group the Kingsport Formation, an Early Ordovician dolomite and limestone whose type section is a road cut beside U.S. 23 just northwest of the city, according to the U.S. Geological Survey. Rock like that dissolves slowly and unevenly over time. What it leaves at the surface is usually a clay-heavy soil: the Dunmore series that NRCS maps across East Tennessee's ridges and valleys, for example, has a subsoil that is 40 to 60 percent clay and areas pitted with limestone sinks.

Two things follow for a wall:

• The footing trench can change under your feet. Firm red clay, soft wet pockets, old fill and ledges of rock can all turn up in one run. A careful contractor digs out the soft spots and builds the base back with compacted stone instead of setting block on whatever happens to be there.
• Clay stays wet. Kingsport gets about 45 inches of precipitation in a normal year. Saturated clay is heavier and pushes harder, so the water behind a wall usually matters more than the wall itself.

What kinds of walls go in here?

• Segmental concrete block. Dry-stacked units that lock together, with geogrid reinforcement layered into the backfill once the wall gets tall. The common pick for terraced backyards, driveway cuts and patio edges. More on block walls.
• Natural stone. Dry-laid limestone or fieldstone, big boulders set by machine, or a stone face on a block or concrete core. It fits older neighborhoods and lots on the bluffs above the river. More on stone walls.
• Reinforced concrete. Poured with steel inside and normally designed by an engineer, it shows up where a wall props up a parking pad, a garage slab or a road.
• Treated timber and railroad ties. Found on a lot of ranch and split-level houses from past decades. Many are rotting now, and most owners swap them for block or stone. More on replacing timber walls.

Why do retaining walls fail?

• No way for water to get out. The same clay dug from the hole went back in behind the wall, there's no drain at the base, or the drain outlet got buried.
• A weak base. Block stacked on loose fill or a thin layer of stone settles unevenly, and the wall starts to rotate forward.
• More height than the design allows. A block wall built past its unreinforced limit without geogrid, or a tie wall with no anchors running back into the hill.
• Loads nobody planned for. Cars parked at the edge, a shed or pool set close to the top, or fill dumped on the slope above.
• Rot. Wood walls lose strength from the back and bottom first, where you won't see it until the face starts to lean.

Read about fixing a failing wall.

Warning signs worth a call

• The top edge tipping out farther than the base
• A bulge partway along the face
• Caps lifting, blocks slipping forward, or stones dropping out
• Soft or split timbers, or a gap opening between the wall and the soil
• Mud washing out of joints or from under the bottom course after rain
• A crack or a sag in the lawn, driveway or patio just behind the wall

Will I need a permit?

Possibly. The City of Kingsport enforces the 2018 International Residential Code, and its building FAQ says a permit is needed for any new construction or renovation other than cosmetic repairs, with grading on its list of permitted work. The FAQ doesn't spell out a rule for retaining walls, so check with the Building Division at 415 Broad Street before you assume a wall is exempt. As a baseline, the model code exempts walls 4 feet tall or less, measured from the bottom of the footing, unless they hold back extra load like a driveway, a building or a slope above them. In Kingsport, the contractor you hire pulls the permit. Outside city limits, Sullivan County, Hawkins County and towns like Church Hill run their own offices. The Kingsport retaining wall guide has the details.

Are you a retaining wall company?

No. Kingsport Retaining Walls is a referral service. We connect you with an independent contractor that works in your area, and that contractor designs, prices, builds and warranties the job. Before you sign, read our tips for hiring a wall contractor.

Areas we cover

• Kingsport
• Colonial Heights
• Church Hill
• Blountville

Planning ahead? Read our Kingsport retaining wall guide.