A retaining wall does not fail all at once. It bulges a little, then leans a little more, and then one spring a section lets go.
The good news is that a wall caught early is usually repairable for a fraction of a rebuild. The bad news is that most people call after it has moved twice.
Signs Your Wall Is Failing
- Bulging in the middle of a run, where the face pushes outward
- Leaning forward at the top
- Blocks separating or stepping out of line
- Cracking through blocks rather than at joints
- Soil or mulch washing through the face
- Standing water behind the wall after rain, or water weeping through it
- The ground above the wall settling or pulling away
- Seasonal movement, where it looks worse every spring than it did in fall
That last one is the frost tell and it means water is in the backfill.
What Actually Causes It
No drainage behind the wall, or drainage that plugged. This is most of them. Water trapped behind a wall creates hydrostatic pressure that pushes outward on the whole face. A drain system that was never installed, or one installed without filter fabric that silted up over a few seasons, produces the same result.
A base that failed. Not deep enough, not compacted, or not below the frost line. The wall moves because what it is sitting on moves.
Frost. Saturated backfill freezes, expands and jacks the wall. It does not come back down evenly.
Wrong wall for the load. A wall built for a decorative two foot grade holding back six feet of saturated clay, or a wall with a driveway above it and no reinforcement for that load.
Age in timber walls. Wood against wet soil rots from the back. The face can look fine while the structure behind it is gone.
Repair or Rebuild
Honest version: it depends on what is actually failing, and that takes pulling a few blocks and looking.
Repair makes sense when the base is sound, movement is limited to one section, and the problem is drainage. We excavate the backfill, install rock, fabric and drain tile properly, reset the affected blocks and put it back. You keep the wall and most of the material.
Rebuild is the answer when the base has failed, the wall has moved significantly along its whole length, the original build was wrong for the load, or it is a timber wall that has rotted. Patching any of those buys a season or two at most.
We will tell you which one you have. We would rather give you the real answer than sell you a repair that fails again next spring.
What We Do on a Repair
- Walk the wall and identify what is moving and why
- Excavate the backfill behind the affected section
- Inspect the base and the existing drainage, if any
- Install clean drain rock, filter fabric and perforated drain tile with an outlet to daylight
- Reset or replace the affected blocks
- Backfill, compact and restore the grade above
- Finish the disturbed ground with rock, mulch or plantings or hydroseeding
Retaining Wall Repair Questions We Get
Often yes, if the base under the rest of the wall is sound. We will know once we open it up.
Sometimes. Block lines change over the years. If an exact match is not available we will show you the closest option before we start.
No. A wall that moves in two years was built without drainage, without a proper base, or both. Worth knowing before you decide whether to repair it.
A wall that is bulging is under load and gets worse, not better. A failing wall also takes the slope with it, which turns a wall problem into a grading and erosion problem. Earlier is always cheaper.
Get Your Wall Looked At
Send a few photos or call and describe what it is doing. We will tell you straight whether it is a repair or a rebuild.
Request a free quote or call (651) 775-4446.
