A retaining wall holds back soil so you can use ground that used to be a slope. Done right, it stops erosion, creates level space for a lawn or patio, and adds structure to the landscape. Done wrong, it leans, bulges, or falls over within a few years, almost always because of a thin base or no drainage behind the wall.
We build segmental block walls, the interlocking concrete units you see in the photo on this page, on a compacted gravel base with drainage stone and pipe behind them. That is the part you never see once the wall is finished, and it is the part that keeps it standing.
What is included
- Layout and height planning based on the slope and what you want to use the space for
- Excavation and a compacted, leveled gravel base
- Buried first course for stability
- Drainage aggregate behind the wall and perforated drain pipe at the base
- Geogrid reinforcement on taller walls where the design calls for it
- Caps, steps, and corners finished cleanly
- Backfill, grading, and planting or sod on the finished grade
How the job works
- 1Assess the slope. We look at height, soil, drainage, and what sits above the wall, like a driveway, fence, or house.
- 2Plan and quote. You get a written plan with wall length, height, block style, and drainage details.
- 3Build the base. We excavate, compact gravel in lifts, and set a level first course below grade.
- 4Stack, drain, backfill. Courses go up with drainage stone behind them and a drain pipe at the base, then the wall is capped and backfilled.
Retaining walls on Midlands clay and sand
Red clay is the biggest threat to a retaining wall in the Columbia area. Clay holds water, and wet clay is heavy. After a week of rain, the pressure behind an undrained wall can be enough to push it forward. That is why every wall we build has free-draining stone behind it and a pipe at the base to carry water out.
Sandy soils fail differently. Sand washes out from under and around a wall if water is allowed to run through it, which undermines the base. Filter fabric and a well-compacted base keep the sand in place.
Heavy summer storms and tropical rain are what test a wall. Our hurricane season can bring several inches of rain in a short time, and walls that seemed fine for years sometimes move after one of those events. Building the drainage in from the start is far cheaper than rebuilding.
Taller walls, generally anything over about four feet, or walls holding up a driveway or structure, usually call for an engineered design and may need a permit. We will tell you up front if your project is in that range and what it means.
What affects the price
Every property is different, so we quote each job after seeing it. These are the things that move the number most:
- Length and height of the wall, measured in face square feet
- Block style and color
- Excavation required and soil conditions
- Drainage requirements and distance to an outlet
- Steps, curves, corners, and caps
- Access for equipment and material delivery
- Engineering or permitting for taller walls
Quotes are free, and our customers regularly mention that we stick to the price we quote.
Timeline and warranty
A small garden or bed wall can be done in a day or two. Longer or taller walls typically take several days to a week or more, depending on excavation and access.
Ask about warranty coverage when we quote your project, and we will put the terms in writing.