A retaining wall has a demanding job. It must hold back soil while managing water, changing temperatures and the weight of the landscape above it. When one part of the system is designed or installed incorrectly, the wall may begin leaning, bulging, separating or sinking.
The Quad Cities’ seasonal moisture and freeze-thaw cycles make proper construction especially important. A retaining wall should be treated as a structural landscape system, not simply a row of decorative blocks.
Common Signs of Retaining-Wall Failure
- A wall leaning away from the soil
- Blocks that have shifted or separated
- Bulging sections
- Cracked masonry or concrete
- Uneven or sinking courses
- Soil washing through joints
- Water collecting behind or below the wall
- Erosion near either end
- Stairways, patios or landscaping settling above the wall
Small changes do not always mean immediate failure, but visible movement deserves attention. Retaining-wall problems normally become more expensive after additional soil and water pressure worsen the damage.
Poor Drainage Is a Leading Cause
Water is one of the greatest threats to a retaining wall. Saturated soil becomes heavier and creates additional pressure behind the structure. If the water cannot escape, that pressure pushes outward against the wall. During winter, trapped moisture can freeze and expand.
A properly designed wall may use free-draining aggregate, filter fabric, drain tile or another suitable outlet, grading that directs surface water appropriately, and drainage openings where the system requires them. The correct solution depends on the site.
An Inadequate Base Can Cause Settling
A retaining wall is only as stable as the foundation beneath it. Placing blocks directly on loose soil or an insufficient layer of base material can allow sections to settle unevenly.
Proper preparation generally includes excavation, suitable compacted aggregate and careful leveling. The first course is particularly important because every course above it follows the same foundation.
Taller Walls May Need Reinforcement
As a wall becomes taller, the forces acting against it increase. Depending on its height and site conditions, the system may require geogrid or another engineered reinforcement method.
Walls supporting driveways, structures, steep slopes or other significant loads may require additional design and permitting considerations. Those factors should be evaluated before construction begins.
Improper Materials Can Shorten a Wall’s Life
Retaining-wall materials should be chosen for structural performance as well as appearance. The selected system needs to be appropriate for the wall’s intended height, soil and drainage conditions, curves, corners and steps, the load above the wall, local weather exposure and the desired appearance.
Materials designed primarily for decorative edging may not be suitable for a wall holding back a substantial grade.
Water at the Top of the Wall Matters Too
Downspouts, sump-pump discharge, irrigation, sloped pavement and neighboring grades can direct concentrated water toward a retaining wall. That runoff may saturate the soil or cause erosion around the ends.
A complete plan considers where water begins, how it moves across the property and where it will discharge after passing through or around the wall.
Can a Failing Retaining Wall Be Repaired?
Some walls can be repaired, but the right decision depends on why the wall moved. Rebuilding only the visible section will not provide a lasting solution if the original failure was caused by poor drainage, an inadequate base or missing reinforcement.
An assessment should consider how far the wall has moved, whether movement is continuing, wall height and condition, drainage, the foundation, loads above the wall, material condition and equipment access.
Planning a New Retaining Wall
- What soil or grade will the wall retain?
- Where does water currently travel?
- What is located above the wall?
- How tall and long will the wall be?
- Is equipment access available?
- Will steps, patios, walkways or planting beds connect to it?
- Are permits or engineered plans required?
Answering these questions early leads to more accurate planning and fewer surprises during installation.
JC Landscape & Maintenance designs and installs retaining walls throughout the Quad Cities. Our hardscaping services can coordinate walls with patios, walkways and the surrounding landscape so the finished project functions as one outdoor space.
Request a Retaining-Wall Consultation
If an existing wall is leaning, separating or showing drainage problems, waiting may allow further movement. If you are planning a new wall, early evaluation helps determine the appropriate materials, drainage and construction approach.
Call JC Landscape & Maintenance at (563) 388-8888 or request an estimate for retaining-wall installation or assessment in Davenport, Bettendorf, Moline and the surrounding Quad Cities.