Retaining Wall Repair in Sandy Springs, GA

Most retaining walls fail slowly, and nearly always because of water. We repair block, boulder and timber walls across Sandy Springs, and we start with the drainage behind the wall, not just the face you can see. If a repair will not hold, we will tell you so.

Signs your retaining wall needs attention

Most retaining walls give warning before they fail. The trouble is that the signs come on slowly. A wall you walk past every day can lean another inch over a year without you noticing. Look at your wall with fresh eyes a couple of times a year, ideally after a long stretch of rain.

Watch for these:

One of these on its own is not always serious. A single loose cap block is a quick fix. A lean combined with soil washing out at the base is a different matter, and someone should look at it before the next heavy storm.

• A lean or bulge, where the face of the wall tips forward or bows out in the middle
• Blocks or caps that have shifted, slipped or come loose
• Cracks that run up through the wall, or step-shaped cracks in a mortared wall
• Soil washing out from the base or through gaps between units
• Water pooling behind the wall, or a wet, soft strip of lawn along the top
• Timbers that are soft, split or pulling away from their tiebacks
• A fence, patio or driveway above the wall that has started to sink or tilt

What usually causes a wall to fail

Nearly every failing wall comes back to water. When rain soaks the soil behind a wall and has nowhere to go, the soil gets heavier and pushes outward. A wall built to hold back damp soil is now holding back something much heavier. This is called hydrostatic pressure, and it is the main reason walls lean.

A properly built wall has a few things behind it that you never see: a layer of clean gravel for drainage, a perforated pipe at the base that carries water away, and on taller block walls, sheets of geogrid that tie the wall back into the hillside. When any of those are missing or clogged, the wall works against the slope instead of with it.

Other common causes:

• A base that was not dug deep enough or compacted properly, so the bottom course settles unevenly
• A wall built taller than its design allows, without reinforcement
• Tree roots growing behind or under the wall
• Downspouts, or a neighbor's yard, draining straight onto the wall
• Rot in timber walls, which usually starts where the wood meets wet soil
• Extra weight added above the wall later, such as a driveway, a shed or a parked car

Repair or rebuild: how we decide

Not every wall that looks bad needs to come down. We decide based on what is causing the problem and how far it has gone.

Repair usually makes sense when the damage is limited to one section and the rest of the wall is straight and solid. It also makes sense when the cause can be fixed from the surface, such as a blocked drain outlet or a downspout aimed at the wall, or when only a few blocks, caps or timbers need resetting or replacing.

Rebuilding a section, or the whole wall, is usually the better choice when the wall leans along most of its length, when there is no drainage behind it and the soil stays wet, when the base has failed and the bottom course has moved, or when timbers are rotted through in several places.

We will tell you plainly which side of that line your wall is on. A patch on a wall with no drainage tends to last a season or two, and we would rather you know that before you decide.

How repairs differ by wall type

Each type of wall fails in its own way, so the repair looks different for each.

Block walls

Boulder walls

Timber walls

What a repair visit involves

A visit starts with a walk along the wall. We check the lean, look at the base, find any drain outlets and where they lead, and note what sits above the wall. We often probe the soil behind it to see how wet it is and whether there is any gravel back there at all.

Then we explain what we think is going on and what we would do about it. That covers how much of the wall needs to come apart, whether we need equipment in your yard, and how we will leave the area when we are done. You get an estimate before any work starts.

If a wall is actively moving or has partly collapsed, keep people, pets and cars away from both the top and the base, and call us. We work Monday through Saturday and will tell you honestly how soon we can get there.

Retaining walls in Sandy Springs

Retaining walls in Sandy Springs work harder than walls in flatter places. Many lots here slope down toward the Chattahoochee and the creeks that feed it, and plenty of driveways and backyards only exist because a wall is holding the hillside back.

Soil is the other factor. Much of the area sits on Georgia red clay, which holds water and swells when wet. Clay behind a poorly drained wall stays heavy for days after a storm. Summer here brings hard afternoon thunderstorms that drop a lot of rain in a short time, and that is often when a weak wall finally moves.

The age of a neighborhood matters too. Many older streets have timber walls put in decades ago that are now reaching the end of their life. Newer infill homes often have tall block walls where the lot was cut to fit a larger house, and those walls depend on the geogrid and drainage being done right the first time. We see the same clay and slopes in nearby Dunwoody, Roswell and Brookhaven, and the same repairs apply there.