Retaining walls in Charleston
A retaining wall fails from behind. The water that builds up in the soil pushes it over long before the block gives out. We set every wall on a compacted gravel footing with the first course buried, backfill it with drainage stone and run a pipe along its base, so the water leaves before it can push.
We price a wall by the area of its face, its material and its height. Send a photo and a rough length and height, and you get the number the same day.
- Built in
- Segmental block, natural stone or brick
- Footing
- Compacted gravel, first course buried
- Drainage
- Stone backfill and a pipe to daylight
- Warranty
- Two years on our workmanship
- Part of
- Our hardscaping work
Retaining wall construction that holds its line.
- The wall laid out and its height checked against the permit line
- A trench dug and a compacted gravel footing laid, with the first course buried
- Block or stone set level, each course stepped back into the slope
- Drainage stone behind the wall and a perforated pipe at its base, run to daylight
- Geogrid in the backfill on taller walls, as the block maker specifies
- Caps set, and the ground above and below finished
The square footage of the wall face you can see. Height and material set the range.
What a retaining wall costs in Charleston: height and material set the range.
A low garden wall and a four-foot wall holding a driveway are different jobs. The taller the wall, the more of it sits underground and behind, where the cost is.
Roots, old footings and wet clay turn up behind walls. If we find soil that will not hold a footing, you hear about it and the fix before we build on it.
A retaining wall, before and after.
Why retaining walls lean, and how we stop it
Most leaning walls tell the same story: no drainage behind it, a footing on loose soil, and block stacked straight up instead of stepped back. Water fills the soil after a storm and the soil pushes. Stone backfill and a pipe let the water out before it builds.
Charleston is flat, so most walls here are low: a raised patio, a bed lifted out of wet ground, a terrace behind the house, a wall along a drive cut into a slope. Low walls still need the footing and the drainage. They fail slower without them.
Permits, easements and HOAs for retaining walls
Four feet is the line. Under the residential code South Carolina uses, a wall four feet tall or less, measured from the bottom of the footing to the top of the wall, needs no building permit unless it holds back extra load, like a driveway or a slope above it. Taller walls need a permit and an engineered design, and we tell you which side of that line yours falls on before we quote.
Easements need the city. In the City of Charleston, anything placed in a city drainage or access easement needs the city’s encroachment permit, and a wall is no exception. We check the plat before we lay it out.
HOAs and the historic districts. HOAs expect to approve wall material and color, and downtown the Board of Architectural Review looks at walls visible from the street. We put the package together with you.
- Where we build
- Charleston, North Charleston, Mount Pleasant, James Island, Johns Island, West Ashley, Daniel Island, Summerville, Hanahan and Goose Creek.
Retaining wall questions Charleston homeowners ask us.
Do I need a permit for a retaining wall in Charleston?
Not for a wall four feet tall or less, measured from the bottom of the footing, unless it holds back a driveway or a slope. Taller walls need a permit and an engineered design. HOAs and, downtown, the Board of Architectural Review may want to see any wall.
Why do retaining walls fail?
Water. Soil behind a wall with no drainage fills up after a storm and pushes. A footing on loose soil and courses stacked straight up make it worse.
Block or natural stone?
Block costs less, goes up faster and comes in engineered systems for taller walls. Natural stone costs more and looks like it has been there a century.
Can you fix a leaning wall?
Sometimes a section can come down and go back up on a proper footing with drainage behind it. A wall leaning along its whole length needs rebuilding. We tell you which after we see it.
What is a seating wall?
A low freestanding wall at sitting height, capped wide enough to sit on, around a patio or a fire pit. It holds nothing back, so it needs a footing but not the drainage of a retaining wall.
How long does a retaining wall take?
A low garden wall takes a day or two. Longer and taller walls take longer, and most of that time goes into the digging and the footing.
Send the slope, take the price.
A photo, a rough length and height, and what the wall holds up. That is enough for a real number the same day.