Your Complete Guide to Kentledge Blocks (Kelly Blocks)

Whether you’re securing scaffolding against fierce winds, anchoring marquees, or providing counterweights on cantilevered structures, concrete kentledge blocks provide the rigidity and stability you need to keep your sites safe and stable.

At Maltaward, we’ve witnessed just how these versatile and robust concrete blocks transform potentially dangerous or hazardous situations into secure environments that offer peace of mind and reassurance. 

But what exactly are kentledge blocks, and why have they become important when it comes to securing vacant properties, conducting renovation work, and more?

What Are Kentledge Blocks?

Kentledge blocks, also known as kelly blocks or hoarding blocks, are high-density concrete weights specifically engineered to provide ballast and counterweight solutions. 

The term “kentledge” dates back to the 1600s, possibly derived from the old French “quintelage,” meaning ballast, and “quintal,” a hundredweight unit of mass. While originally confined to being nautical ballasts in a ship’s hold, nowadays, kentledge blocks serve a far broader purpose.

These aren’t just heavy-duty concrete blocks; they’re precision-engineered products designed with specific weight distributions, lifting points, and connection systems to maximise stability whilst maintaining practicality and safety.

Why Kentledge Blocks Are Important in Construction

The UK building industry has changed dramatically in recent years, with temporary structures now common. As such, these structures, being not fixed to the ground, require sophisticated support and stability. Traditional methods of securing scaffolding, hoarding and other building installations often require extensive groundwork, which can be costly, time-consuming, and, depending on the surface, often impractical.

Kentledge blocks alleviate this problem by providing above-ground stability and rigidity that eliminate the need for excavation, not to mention reduce installation time, and offer an excellent amount of flexibility. The weight of kelly blocks ranges from 500kg to over 1,000kg, creating a virtually immovable foundation that can withstand significant wind loads and external forces.

Where Can Kentledge Blocks Be Used?

• Site hoarding and perimeter fencing – which is ideal when ground excavation is prohibited or unfeasible, or when underground services make digging dangerous.

• Scaffolding – kentledge blocks act as reliable ground anchors and tie-backs without the need to drill into the ground. The blocks can also be mechanically integrated into the steel framing itself.

• Marquees – these blocks can be used to anchor temporary marquees by being strapped to the main supports, providing a stable base that doesn’t damage underlying surfaces and that can be quickly deployed.

• Stageworks and rigging – these blocks can act as ideal counterweights for cantilevered structures, lighting gantries and other tubular structures where traditional foundations aren’t realistic.

Alongside anchorage, kentledge blocks can also be used for cranes or as ballast weights, where they can be stacked simply and securely without worry.

Kentledge Block Specifications

Modern kentledge blocks come in various configurations. At Maltaward, we offer blocks in two primary weights:

1000kg Kentledge Blocks

• Dimensions: 1030mm x 750mm x 750mm
• Ideal for heavy-duty applications
• Perfect for scaffolding and major structural support

500kg Kentledge Blocks

• Dimensions: 1025mm x 430mm x 580mm
• Suitable for lighter applications
• Excellent for hoarding and temporary installations

Both these types of kelly blocks are made from high-strength concrete, and come with integrated lifting points for safe handling with approved heavy lifting equipment and machinery. They feature a stackable design for effective storage and transport, and are finished with a weather-resistant coating to improve durability.

Why Use Maltaward Kelly Blocks?

What sets Maltaward’s kentledge blocks apart isn’t just their robust construction; it’s our comprehensive approach to safety, security and reliability. We don’t simply supply concrete blocks for hire or purchase; we offer a complete tailored safety solution to each of our customers, backed by over 30 years of industry experience. 

We can offer:

• Expert consultation on the recommended block configuration
• Nationwide delivery with flexible scheduling
• Both hire and purchase options to suit project budgets
• Integration with our broader range of concrete barriers and security services, such as steel doors, window screens, fencing, gates, and more

Final Considerations

Working with kentledge blocks requires adherence to strict safety protocols, being mindful of long-term costs versus your initial investment, and the environmental implications of your choice. 

Their substantial weight demands proper lifting equipment (HIAB cranes fitted with block grabs) and trained personnel. Always use appropriate lifting equipment rated for the block weight, inspect lifting points, ensure stable, level surfaces for block placement, and be mindful of wind loading. Remember to follow the manufacturer’s guidelines for stacking and configuration.

While the initial investment in kentledge blocks might seem substantial, they offer exceptional long-term value because they:

• Can be reused and repurposed across multiple projects
• Don’t need excessive ground preparation 
• Can be installed and repositioned easily with proper equipment
• Don’t need to be maintained or treated
• Can be hired instead of purchased, if preferred

Modern kentledge blocks are 100% recyclable and designed for decades of repeated use

Choose the Right Kentledge Blocks

Ready to discover how kentledge blocks can enhance your project’s safety and efficiency? Contact our expert team today for a free, no-obligation consultation.