Retaining Wall Guide

WHY RETAINING
WALLS FAIL

When a retaining wall begins leaning, shifting or losing ground around it, the visible movement is usually the end of the story — not the beginning. Something changed the forces acting on the wall or the ground around it. Water is one of the first things to investigate.

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1. Water builds up
behind the wall

Soil becomes heavier when it holds water, and trapped water adds pressure behind retained ground.

If runoff is continually being sent toward the wall or water cannot leave the area appropriately, the wall is being asked to handle more than dry soil alone.

That is why retaining work and drainage should be planned together.

2. The surrounding grade sends
water the wrong way

A wall can have drainage behind it and still be surrounded by a bad water pattern.

If the property funnels runoff toward the top, ends or base of the wall, erosion and repeated saturation can continue causing problems.

The grade around the wall matters.

3. The base or supporting
ground changes

Retaining walls depend on stable support.

Erosion, settlement or poor ground conditions around the base can allow movement even when the visible wall originally appeared solid.

4. Erosion removes ground
around the ends or toe

Water does not have to push directly behind the wall to cause trouble.

Runoff can remove supporting soil at the lower edge, wash around an end or create a channel beside the wall.

Once the surrounding land begins moving, the wall may follow.

5. The property changes

Driveways, pads, added fill, altered drainage routes and other site changes can affect how water and loads interact with an existing retaining area.

A wall should be evaluated in the context of the current property rather than only the conditions that existed when it was first built.

What should you do with
a wall that is moving?

Do not begin by assuming it only needs cosmetic repair.

Look for:

– where water is coming from
– whether the surrounding grade changed
– erosion around the wall
– soft or saturated areas
– changes above or below the slope

The goal is to understand WHY movement is occurring before deciding what needs to be rebuilt, regraded or drained.

Repair, rebuild or
change the slope?

The appropriate response depends on the condition of the wall and the property.

Some situations may require new retaining work.

Others may benefit from changing the grade or correcting water movement.

The important decision is not simply how to straighten the visible wall. It is how to prevent the property from recreating the same conditions.

Common questions

Is water really one of the main causes of retaining-wall problems?

Water is often a major contributor because it increases pressure, saturates soil and can erode supporting ground. The full property should still be evaluated rather than assuming every failure has one cause.

Can drainage correction save an existing wall?

That depends on the wall\u2019s condition. Correcting drainage may stop the conditions from getting worse, but a wall that has already moved significantly may need additional work.

Why does a wall lean outward?

Movement can result from pressure behind the wall, support loss, water, surrounding grade conditions or a combination of factors. The cause needs to be evaluated on site.

A moving wall is
telling you something.

Find the cause before deciding on the repair.

Let's get your project
done the right way.

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