Introduction
As a homeowner, you invest time and money into creating a beautiful, functional outdoor space. Retaining walls—whether for garden terraces, driveway borders, or structural support—play a crucial role in landscaping. But what happens when water pressure silently builds up behind these walls, leading to catastrophic failure?
This phenomenon, known as “kickout failure,” occurs when hydrostatic pressure (water buildup) overwhelms a retaining wall’s structure, causing it to crack, lean, or even collapse. The good news? With proper design, materials, and drainage solutions, you can prevent this costly and dangerous issue.
In this article, we’ll explore:
- What causes kickout failure
- How to recognize early warning signs
- The best retaining wall products to prevent failure
- Professional installation techniques that ensure long-term stability
For expert solutions, check out WonderWalls—Australia’s trusted provider of precast reinforced concrete walls and professional installation services.
What Is Kickout Failure?
Kickout failure happens when water pressure behind a retaining wall exceeds the wall’s structural capacity. Instead of holding back soil, the wall “kicks out” at the base, leading to tilting, cracking, or total collapse.
Why Does It Happen?
- Poor Drainage – Without proper drainage (weep holes, gravel backfill, or drainage pipes), water accumulates behind the wall, increasing pressure.
- Weak Foundations – If the footing isn’t deep or wide enough, the wall can’t resist the lateral force of water-logged soil.
- Inferior Materials – Low-quality blocks or unreinforced walls lack the strength to withstand pressure over time.
- Heavy Rainfall or Poor Grading – If the surrounding landscape directs water toward the wall, pressure builds rapidly.
Signs Your Retaining Wall Is at Risk
- Bulging or leaning (even slight tilting is a red flag)
- Cracks in the wall or footing
- Water seepage at the base
- Soil erosion behind the wall
If you notice these signs, it’s time to take action before failure occurs.
How to Prevent Kickout Failure: The Right Materials & Design
1. Choose the Right Retaining Wall System
Not all retaining walls are created equal. For long-term durability, consider:
Precast Reinforced Concrete Walls
- Superior strength – Engineered to resist hydrostatic pressure.
- Precast construction – Ensures consistency and reduces weak points.
- Customizable finishes – Available in various textures and colors to match your landscape.
WonderWalls offers high-quality precast concrete walls designed to prevent kickout failure.
Segmental Retaining Walls (SRWs) with Geogrid Reinforcement
- Interlocking blocks provide stability.
- Geogrid layers extend into the soil, anchoring the wall.
- Built-in drainage reduces water pressure.
2. Install Proper Drainage Systems
Even the strongest wall can fail without drainage. Key solutions include:
- Perforated Drainage Pipes – Installed behind the wall to redirect water.
- Gravel Backfill – Allows water to flow freely instead of pooling.
- Weep Holes – Small openings at the base to release water.
3. Ensure a Strong Foundation
A retaining wall is only as strong as its footing. Best practices include:
- Excavating deep enough (below frost line if applicable).
- Compacting the base to prevent settling.
- Using reinforced concrete footings for heavy-duty walls.
For expert installation, WonderWalls provides professional retaining wall services to ensure your wall is built to last.
Case Study: How a Properly Installed Wall Resists Water Pressure
Imagine two neighboring homeowners:
- Homeowner A installed a DIY timber wall with minimal drainage. After heavy rain, the wall bowed and collapsed.
- Homeowner B chose a precast reinforced concrete wall with a gravel backfill and drainage pipe. Years later, their wall remains perfectly stable.
The difference? Proper materials, drainage, and professional installation.
When to Call a Professional
While small garden walls can sometimes be DIY projects, taller or load-bearing walls require expert engineering. If your wall:
- Is over 1 meter tall
- Supports a driveway, slope, or structure
- Shows signs of stress (cracks, leaning)
…then it’s time to consult a specialist. WonderWalls’ installation team ensures your wall meets engineering standards and local regulations.
Conclusion: Protect Your Investment with the Right Wall
Kickout failure is preventable—if you use the right materials, drainage, and construction techniques. Whether you need a decorative garden wall or a structural precast concrete retaining wall, investing in quality now saves costly repairs later.
For durable, engineered solutions, explore WonderWalls’ product range and professional installation services.
Don’t let water pressure destroy your hard work—build a wall that stands the test of time!
