Block, stone, timber, repair
Retaining walls in Marietta, GA
New retaining walls and repairs for sloped Cobb County yards. Block is the most common choice, stone is the premium look, and timber is the budget option. Every quote includes the gravel backfill and drain pipe behind the wall.
01 Block
Segmental block retaining walls
Interlocking concrete units stacked without mortar, each course set back slightly into the hill. They are the go to wall for backyards, driveways and terraced beds because they are predictable to build and commonly last 40 years or more.
- Concrete landscape blockLow walls, garden beds$30 to $75 / sq ft
- Segmental retaining wall blockTaller walls with geogrid$40 to $90 / sq ft
Typical installed ranges per sq ft of wall face. Source: LawnStarter retaining wall cost guide (2026).
02 Stone
Natural stone and boulder walls
Dry stacked fieldstone, cut stone or large boulders. Stone suits lower garden walls, terraced planting beds and walls next to patios where the look matters. Fitting stone is slow, skilled work, which is most of the cost.
- Natural stoneDry stacked or mortared$45 to $110 / sq ft
- Poured concreteStructural, tight footprints$60 to $120+ / sq ft
Typical installed ranges. Source: LawnStarter retaining wall cost guide (2026).
03 Timber
Treated timber walls
Pressure treated 6x6 timbers with tiebacks into the slope. Timber is the lowest upfront cost and fits short garden walls, but wet clay shortens its life, often to 15 to 25 years. Many East Cobb and Marietta yards still have timber walls from older subdivisions that are reaching that age now.
- Pressure treated timberShort walls, budget projects$20 to $50 / sq ft
Typical installed range. Source: LawnStarter retaining wall cost guide (2026).
04 Repair
Leaning, bulging or cracked wall repair
Signs a wall needs attention: a belly in the middle, blocks pushing out, gaps opening at the top, soil washing out at the base, soft or split timbers, or water seeping through the face. Most of these trace back to water with nowhere to go.
- Typical repairCracks, seepage, a few units$450 to $950
- Rebuild or replaceShifted base, long sections$6,000 to $14,500
- Structural engineerSevere movement, tall walls$100 to $220 / hr
Sources: Angi retaining wall repair cost (2026); Angi retaining wall cost (2026). Typical ranges, not quotes.
Walls over 4 feet
When a wall needs a permit and an engineer
Under the rules for unincorporated Cobb County, a retaining wall over 4 feet tall, or one holding up a driveway, structure or slope above it, generally needs a building permit and plans stamped by a Georgia licensed professional engineer. Walls 4 feet or less holding plain soil are generally exempt. Cities inside the county, including Marietta, Kennesaw and Smyrna, can set their own rules. Your quote states which applies to your address. Source: Cobb County residential permitting.
Need water moved, not just held back? See French drains and yard drainage.
FAQ
Retaining wall questions
What is the best retaining wall material for Georgia clay?
For most Cobb County yards, segmental concrete block is the safest choice. It handles clay well when it sits on a compacted gravel base with gravel backfill and a drain pipe behind it. Natural stone works well for lower garden walls. Timber is the cheapest but rots fastest in wet clay.
How tall can a retaining wall be without an engineer?
In unincorporated Cobb County, walls 4 feet or less that do not hold up a driveway, building or slope generally do not need a permit. Taller walls, or walls carrying a load above them, generally need a permit and plans stamped by a Georgia professional engineer. City rules can differ, so it gets checked for your address.
How long does a retaining wall last?
Treated timber often lasts about 15 to 25 years. Segmental block and natural stone commonly last 40 years or more when the base and drainage are built correctly.
How much does retaining wall repair cost?
Angi's 2026 data puts typical repairs at $450 to $950, with cracking and seepage fixes on the lower end. A wall that has shifted at its foundation may need a section rebuilt, and full replacement commonly runs $6,000 to $14,500.
Is it worth repairing an old timber wall?
If only a few timbers are soft, a repair can buy time. If the wall is leaning along its length or the tiebacks have rotted, replacing it with block usually costs less over the next 20 years than repeated fixes.
Get a free retaining wall quote
Send the wall length, rough height and a photo if you have one. A local crew follows up with a written price.