Don’t Overlook Retaining Walls: Why Professional Inspections Matter

Retaining walls are often a property’s silent protectors. While they may not always draw attention, they serve critical functions: preventing erosion, managing water runoff, and supporting the landscape.

Like any structure, retaining walls require regular maintenance and inspection to keep them functional. In areas with heavy rainfall or flooding risks, like New Jersey, water accumulation can put tremendous strain on these walls. If drainage systems are not regularly checked and cleared, the excess moisture can weaken the structure over time.

Retaining walls are often considered a common element in community associations and, therefore, conducting an inspection of them during a Reserve Study Inspection is important to identify issues before they escalate. With this evaluation, homeowner’s associations (HOAs) in New Jersey can maintain the structural integrity of their retaining walls and prevent costly repairs down the line. In addition, for many commercial facilities, there are retaining walls installed on the site which can be inspected when performing a property condition assessment NJ.

The Role of Retaining Walls

A retaining wall is a structural barrier built to resist the lateral force of soil or other materials on one side. It is typically used to support and stabilize slopes, hillsides, or uneven terrain by holding back earth or water.

Retaining walls are constructed to address numerous structural, environmental, and practical needs. These may include the following:

1. Prevent Soil Erosion

Soil erosion can cause the land to become unstable and increase the risk of shifting or collapsing. Retaining walls prevent this by holding the soil in place and stopping it from being washed away due to rain or other forces.

2. Support Steep Slopes

Steep terrain presents challenges for the construction of roads, buildings, and other structures. Retaining walls stabilize slopes and provide the necessary support for landscaping and functional outdoor spaces.

3. Manage Water Runoff

A structural engineer NJ designs retaining walls with features such as weep holes, perforated pipes, or gravel backfill. These components allow water to drain through or around the wall, reducing hydrostatic pressure and preventing water buildup.

4. Add Aesthetic Value

In an HOA-managed community, retaining walls contribute to the aesthetics of the property. These structures can be made up of stone, brick, or concrete. When properly integrated into the landscape, retaining walls can add texture, contrast, and depth to the property’s overall design.

Red Flags: Signs of Retaining Wall Issues

The collapse of Wall 22 in Bellmawr, New Jersey, on March 25, 2021, is an example of why retaining walls require professional inspection.

Wall 22 is a major part of the I-295 Direct Connect Project, supporting an elevated roadway not yet open to traffic. According to CBS News, South State reported various warning signs, like soil loss, sinkholes, and cracks, a few years before the incident. Heavy rain exacerbated the wall’s instability, leading to its collapse. Had the roadway been open to traffic or the collapse occurred during peak activity, the consequences could have been catastrophic.

The collapse of Wall 22 serves as a reminder that even seemingly robust walls are not immune to the cumulative effects of environmental pressures and design flaws. Regular inspections and prompt attention to any red flags are essential in preventing similar incidents.

Here are the common warning signs that may indicate a problem with a retaining wall:

1. Cracks or Fissures

Vertical cracks can indicate uneven pressure on the wall, which may be due to poor drainage or shifts in the soil behind the wall. Horizontal cracks, on the other hand, may suggest that the wall is struggling to withstand the weight of the soil behind it. Cracks that appear in a stair-step pattern should also be inspected, as they can signal differential settling or shifting of the foundation.

2. Leaning or Tilting

A wall that leans outward is a critical sign of excessive pressure from the retained soil or water buildup. The tilting of the wall may also be rotational or pivoting around its base. Movements like this suggest that the foundational support may be inadequate.

3. Pooling Water

Accumulated water at the base or behind the wall may be a sign of an inadequate drainage system. The drainage pipes could be clogged, missing, or failing to direct water away effectively.

4. Bulging

Bulging can cause the surface of the wall to appear uneven, with visible protrusions or dips. They are more noticeable at the base or center of the wall, where pressure is highest. Bulging often results in cracks, which may widen over time.

Unaddressed damage can compromise the functionality of the wall. Scheduling an inspection by a professional structural engineer at regular intervals will provide the HOA with a report of the current condition of the wall and any deficiencies observed so they can be addressed and remedied promptly.

The Importance of Professional Expertise

Retaining walls must be built and maintained according to strict engineering standards to maintain their structural integrity and long-term performance. While it may seem tempting for an HOA to manage retaining wall inspections on its own, hiring a licensed engineer is the ideal decision to better assess whether a retaining wall meets these standards.

Professional engineers employ specialized tools like laser levels, total stations, or even drones for more precise measurements of wall movement or settlement. For deeper analysis, they may use soil testing equipment to assess the conditions behind the wall. Engineers also have the expertise to conduct geotechnical testing and the right instruments (e.g., strain gauges or inclinometers) to monitor soil pressures and wall deformations over time.

Professional engineers, using these advanced tools and techniques, provide an accurate and comprehensive understanding of the retaining wall’s condition. With precise measurements and soil analysis, they can identify deficiencies that may not be immediately visible to an untrained eye. This deeper insight allows engineers to provide tailored, appropriate recommendations.

Depending on the case, a NJ structural engineer can recommend the following solutions to retaining wall issues:

• Reinforcing the wall with additional support structures (e.g., geogrid or tieback anchors).
• Installing weep holes or drainage pipes.
• Adding soil reinforcement techniques (e.g., soil nailing or using geotextile fabrics).
• Replacing or repairing damaged or deteriorating wall materials.
• Reshaping the slope behind the wall to reduce pressure and improve stability.
• Conducting soil stabilization treatments.
• Surface coatings or sealants to protect the wall from water infiltration.

Lockatong Engineering for Professional Inspections in New Jersey

Retaining walls are not just an aesthetic element in landscaping. They are essential structural elements that stabilize slopes and prevent soil erosion.

Unstable retaining walls can be extremely dangerous, as they risk collapsing and causing significant property damage or injury. Regular professional assessments are critical to identify early signs of instability and address them before they become major hazards.

Lockatong Engineering offers comprehensive services, including specialized inspections for retaining walls or complete property condition assessments. Our expertise can help property owners and HOAs make informed decisions about necessary repairs, maintenance, or upgrades based on a clear and accurate picture of their property’s condition. With our reliable expertise, communities can mitigate risks, safeguard property investments, and prevent potential disasters.

Contact us today at https://www.lockatong.com/contact-us/ to learn more about our inspection services.