When to Worry About Your Retaining Wall

A retaining wall is a vital part of your property, transforming sloped land into usable space and preventing erosion. It’s designed to withstand immense pressure from the soil behind it, acting as a crucial barrier to protect your landscaping and property. But what happens when you notice that perfect, plumb wall is starting to lean, crack, or bulge?

At Blue Sky Engineering, we understand that these signs can be unsettling. A tilting or bulging retaining wall is rarely just a cosmetic issue—it’s often a clear indicator that something isn’t working as it should. Here’s a guide to the common warning signs and when you should be worried about your retaining wall.

Is My Retaining Wall a Problem? Common Warning Signs

The key to preventing a minor issue from becoming a costly failure is to recognize the early warning signs. Take a close look at your wall for any of the following:

• Leaning or Tilting: This is one of the most obvious signs of a problem. If your wall is visibly leaning outward (away from the retained soil), it indicates that the pressure behind it is overcoming its structural capacity.
• Bulging or Bowing: If a section of the wall appears to be bulging out, it’s a sign that immense pressure from the soil or a water buildup is pushing on that specific area. Excessive water can increase the soil pressure on foundation or retaining walls.
• Cracking: Hairline cracks can be normal with aging, but large, wide, or “stair-step” cracks in concrete or masonry often signal that the wall is under stress and beginning to fail.
• Water Seepage or Poor Drainage: Water is a major cause of retaining wall failure. If you see water constantly seeping through the wall, or pooling at the base after rain, it indicates a lack of proper drainage behind the wall, which leads to increased soil pressure.
• Separation from Adjacent Structures: If the retaining wall is pulling away from your home’s foundation, a fence, or other structures, it’s a red flag that its stability has been compromised.

The Unseen Forces: Why Retaining Walls Fail

A retaining wall’s purpose is to manage powerful, unseen forces. When it fails, it is typically due to one or more of these underlying issues that a basic visual inspection can’t diagnose:

• Hydrostatic Pressure: When water is trapped behind a wall without adequate drainage (like porous gravel, weep holes and French drains), it builds up and exerts a powerful hydrostatic force, which can increase the soil pressure on the wall and lead to failure.
• Inadequate Construction: A number of items can lead to retaining wall failure, including what’s behind it. Lack of proper backfill, drainage, soil compaction at the footing, insufficient footing size, or insufficient reinforcement (reinforcement installation) during construction can lead to failure at a later date.
• Oversized Loads: Putting a heavy object, like a new slab and shed or trees too close to the top of the wall can create a surcharge load that it was never designed to handle.
• Soil and Climate Conditions: Utah’s climate and soil are major factors. Expansive clay soils can swell dramatically when wet, pushing on the wall, while freezing and thawing cycles can cause significant movement and stress.

Your Wall, Built to Last

Don’t let a minor crack become a major collapse. The small investment in a structural assessment now can prevent a much more costly and dangerous project down the road.