The land problem

Rising demands influenced by e-commerce growth and major investment in the warehouse and logistics sector are driving developers to build new large-scale developments at speed on variable ground conditions. This can lead to differential ground movement beneath structures over time, leading to structural issues.  

Some alluvial soils, particularly those high clay content, will swell when wet and sink when dry, causing uneven settlement. Reclaimed coastal sites can often hide deep deposits of soft marine sediment, which may not naturally have the strength or bearing capacity required for heavy structural loads. Additionally, made ground is often composed of poorly compacted fill, bringing the risk of subsurface voids.  

The common theme here is differential settlement, where the ground beneath warehouses and other structures moves at different rates or depths, causing the foundations to sink unevenly into the ground. While the building itself can look structurally sound from the outside, the real problem is hidden beneath the surface.  

Hidden risks of fast delivery 

The rush to get projects over the line quickly may limit the scope for a thorough investigation of the ground conditions before the build. As a result, the chances of settlement issues emerging after construction increase, however, in some cases, settlement-related issues may not become apparent until several years after construction. For warehouse operators and developers, this can lead to significant disruption and costly repairs.  

After Hosetech, a specialist hose and fittings manufacturer based in Little Island, Cork moved into their new warehouse in 2005, cracks began appearing in the concrete slab within months. Surveys revealed the building sat on soft alluvial soil with poor load-bearing capacity reaching as much as 30m below ground level. Settlement in the floor slab was measured at over 148mm between 2008 and 2017. The uneven floor made safe forklift operation and the racking of goods increasingly difficult. 

The true cost of differential settlement  

Warehouses and logistics hubs are extremely fast-paced environments, and any ground-related problems can easily disrupt their daily operations. Settlement can often lead to uneven slabs and cracked floors, increasing wear on equipment such as forklifts and potentially increasing health and safety risks. Even minor differential settlement can lead to reduced accuracy in automated systems or the misalignment of racking.  

All of this can lead to unplanned downtime and disruption to supply chains, which in turn leads to a significant loss in revenue for occupants and asset owners. For example, once floor tolerances exceed safe forklift limits operations are either restricted or stopped. Any faults in racking may require inspection, recertification or reinstallation.  

Depending on the severity of the issue, traditional remediation works may be needed to strengthen the ground or add additional support below the surface. That means parts of the building may need to be vacated temporarily, or operations may need to be suspended in the affected area. In a market where vacancy sits at 3.6%, finding alternative space may not be easy.  

Settlement claims can also lead to difficult conversations with insurers especially around Latent Defects Insurance (LDI), which has strict timelines and exclusions. If the claim falls outside the policy period or the defect wasn't properly documented, the asset owner could have their claim dismissed.  

Addressing the problem 

Traditional remedial works can be costly and disruptive. The process typically involves removing slabs, excavating and re-pouring, and often takes weeks or months to complete. That means suspending operations and vacating occupants, leading to further financial losses. In many cases, however, the issue can be rectified using alternative methods.  

Mainmark specialises in non-invasive ground engineering technology, which can improve the ground and re-level a warehouse without breaking slabs or excavation work. Small injection points (which can be as little as 6mm) are drilled through the existing floor, and resin injection or computer-controlled grouting is injected beneath the slab, re-levelling the affected slabs; often while day-to-day operations continue as normal.  

For Hosetech, this is the exact outcome they were hoping for. “Addressing the sinking warehouse floor was the number one priority for the business,” said Nathanael Ottman, Head of Purchasing at Hosetech. “Resin injection technology gave us a way to achieve this and keep the business running at the same time.” 

These technologies are faster, less disruptive and more cost-effective. More importantly, they help address the underlying ground conditions contributing to settlement and not just the damage.  

Taking action early 

Ireland’s warehouse boom is creating major opportunities for the country, but it also exposes hidden and potentially long-term risks to developers and operators. While structural issues may take years to emerge, their impact on daily operations, revenue and asset value can be significant.  

Mainmark understands the challenges of Irish ground conditions and the commercial pressures that come with them. We work with asset owners, developers and logistics operators to assess risk early and carry out the appropriate remediation works. Early intervention helps lower costs and disruption to sites. If you’re managing a warehouse or logistics site and have concerns about its ground conditions, speak to Mainmark today and find out more.