What Are the Signs of a Failing Retaining Wall?

Cracks in a retaining wall are one of the most obvious signs of trouble. Hairline cracks may be cosmetic, but wider cracks, especially those that run horizontally or diagonally, indicate structural stress. Gaps between blocks or bricks also signal movement, allowing water to seep in and weaken the soil behind the wall.

If you see cracks that grow over time or appear after heavy rain, the wall may be shifting. Water pressure from saturated soil is a common cause. In a humid subtropical climate, heavy rain can saturate the ground quickly. Check for cracks after storms, and if they worsen, consider a professional water damage inspection.

• Cracks wider than a quarter inch
• Horizontal or stair-step cracks
• Gaps between blocks or mortar
• Cracks that reappear after repair
• Cracks with soil or water seeping through

Soil erosion at the base of the retaining wall is a clear warning sign. Look for bare patches, exposed roots, or soil washed away after rain. Water pooling behind or in front of the wall also indicates poor drainage, which increases hydrostatic pressure and can lead to wall failure.

Proper drainage is essential for any retaining wall. If you see water stains on the wall or damp soil that never dries, the wall may be failing. Heavy rain can test your wall's drainage, especially in areas with frequent storms. Check for clogged weep holes or missing drainage pipes, and consider a water damage inspection to assess the situation.

• Soil washed away at the base
• Water pooling behind the wall
• Weep holes blocked or missing
• Damp patches on the wall surface
• Erosion along the slope above the wall

A retaining wall often supports a fence, railing, or another structure. If those elements start to lean or shift, the wall below may be failing. Check for gaps between the wall and the fence posts, or if the fence seems to tilt toward the lower side of the slope.

Movement in the wall can also cause cracks in nearby walkways or driveways. Pay attention to any new dips or uneven surfaces. These signs suggest the ground is moving. Water damage from a failing wall can affect more than just the wall itself, so act quickly to prevent further damage to your property.