To ensure your retaining wall is level, create a perfectly flat and compacted gravel trench first. Lay the base course with a heavy-duty dead-blow hammer, frequently checking with a 2-to-4-foot carpenter's level, and use a tight mason's string line to maintain straightness.
The 1/3 rule is a general guideline for stability: About 1/3 of the wall's total height should be buried below ground. This helps the wall resist the pressure from soil and moisture behind it.
Seven common mistakes when installing retaining wall blocks include poor base preparation, inadequate drainage, not using proper backfill, failing to compact soil, improper alignment of blocks, ignoring wall height limits, and neglecting to use geogrid reinforcement when needed.
Fixing a leaning retaining wall without completely rebuilding it depends on the severity of the lean and the material used. For minor leans (under 2 to 3 inches), you can often stabilize the structure using soil anchors, earth tiebacks, or improved drainage systems to relieve the underlying hydrostatic pressure.
Signs of a Failing Retaining Wall
Sagging or bowing: Chances are, if it looks like your retaining wall is beginning to bend, there may be a problem with the structure itself or what it's holding back.
To level a retaining wall, you must create a perfectly flat, compacted base trench and meticulously adjust the first course of blocks. A stable foundation is the key to preventing wall failure or leaning. Follow these essential steps to ensure a long-lasting wall.
Homeowners insurance covers a retaining wall collapse only if the collapse is directly caused by a "named peril" listed in your policy, such as a vehicle hitting the wall, a lightning strike, or an explosion. If the collapse resulted from normal wear and tear, poor maintenance, erosion, or the weight of saturated soil, it will not be covered.
Avoid DIY Repair Jobs
Unless you fully understand geotechnical issues like earth retention, soil compaction and water drainage, you're simply delaying the problem. For long-term structural support, the resistance and pressure must be precise. This is why you're better off bringing in a professional.
Yes, retaining walls should generally lean back slightly into the soil they are holding back. This backward tilt—known as a "batter"—uses gravity to help the structure resist the immense lateral pressure of the earth and prevents it from toppling forward over time.
A deadman anchor is a structural component buried in the soil behind a retaining wall and connected to it via a tieback (like a cable, threaded rod, or timber tie). It uses passive soil pressure and dead weight to resist the outward pressure of retained dirt, preventing the wall from bowing or leaning over.
Yes, a 3-foot retaining wall absolutely needs drainage. While it is a relatively short wall, trapping water behind it creates immense hydrostatic pressure. Without proper drainage, this pressure, combined with heavy saturated soil, can cause the wall to bulge, crack, or collapse.
Our professional building inspectors often find that retaining wall failures boil down to poor planning, poor installation, and, most commonly, poor drainage.
Foundation bearing (gravity case)
For the following simplified procedure, the “middle third rule” is applied, whereby the wall foundation is dimensioned so that the resultant vertical force acts through the “middle third” of the footing.
If between 1.5-2 metres from boundary, maximum wall height 2 metres. If greater than 2 metres from boundary, maximum wall height 3 metres. If more than 600mm above or below ground level, are contained by a structural support.
Hydrostatic pressure and freeze‑thaw cycles act on any wall that holds back soil, no matter how low. Building codes also step in around 4 feet, where engineering and clear retaining wall drainage requirements are usually mandatory.
Yes, a 2-foot retaining wall generally needs a footing. However, "footing" means different things depending on how the wall is built. Instead of a deep, poured-concrete foundation, shorter walls usually rely on a compacted aggregate base or a single buried row of blocks.
Yes, a retaining wall should always be built true level horizontally, regardless of the slope of your yard. Failing to level the blocks or stones can cause structural failure, as gravity will constantly push the weight downhill.
Without drainage behind a retaining wall, water builds up and causes serious problems. Drainage prevents soil erosion and maintains the structural integrity of the wall. When water has no way to escape, it puts pressure on the wall, known as hydrostatic pressure.
Yes, you should use fabric, but only specific types (geotextiles), and never as a wall wrap or structural support. Standard weed barrier or woven geotextiles clog with silt, trapping water and causing walls to bow or fail. Always use a non-woven geotextile (like 8 oz polypropylene).
When a Leaning Retaining Wall Can Be Repaired
Because retaining walls are frequently considered a detached structure, damage to them can be covered under your homeowners policy under the right conditions. When damage is the result of a “covered loss” — or an insured event — like lightning, wind, fire or a vehicle striking the wall, coverage may be possible.
Over time, the immense pressure of restrained soil and water causes retaining walls to deteriorate and eventually collapse. Bulging, cracked, or leaning retaining walls are in danger of complete failure.
Avoid making guesses or unsupported statements about what caused the damage to your property. Speculating can lead to inaccuracies in the adjuster's report, potentially affecting your claim.
A retaining wall collapse triggers sudden landslides, soil erosion, and severe property damage. The shifting earth can compromise nearby structures, damage home foundations, and pose major safety hazards. Furthermore, standard homeowners insurance usually excludes these collapses, leaving you with out-of-pocket costs.
If you build a business asset (such as a retaining wall that has a legitimate business purpose) that costs >$2,500, you are not allowed to "write it off" (aka expense it all in one year).