1.6m Allegro® Interlocking Concrete Blocks
Heavy-duty modular walling with the most flexible block range
Why choose 1.6m Allegro® Interlocking Concrete Blocks?
The 1.6m Allegro® range is designed for projects requiring maximum strength and flexibility.
- Larger and heavier – weighing 2.46 tonnes per full block, these units offer exceptional stability.
- Seven block types – part of the most comprehensive system, featuring shapes suited for complex layouts and multi-bay designs.
- Build higher walls – engineered to withstand greater surcharges and taller storage walls than smaller Allegro® blocks.
- No fixings needed – blocks lock together through their own weight and nib system, removing the need for bolts or reinforcement.
- A1 fire classification – non-combustible, Class A1 rated, and capable of resisting fire for up to 120 minutes (or 4 hours with sealed joints).
- Long-lasting – unreinforced concrete provides a 100-year design life, even in aggressive environments.
With 1.6m Allegro® Interlocking Concrete Blocks, you’ll get:
Response from the team within 4 working hours
Full technical support, including product datasheets, O&M manuals and CAD files
UK-wide delivery in 2–4 weeks
Stronger blocks for bigger loads and higher walls
When you need interlocking concrete blocks capable of building higher and supporting heavier loads, the 1.6m Allegro® range is the ideal choice. Each block measures 1,600mm × 800mm × 800mm and weighs approximately 2,460kg. The increased size and weight provide these blocks with greater stability and strength, while the wider range of shapes makes it easy to create complex layouts and multiple storage bays.
With seven different block types available, the 1.6m Allegro® system is the most comprehensive and versatile in the range. From spreader blocks that add stability to base rows to sloped-end and flat-top blocks that help material shedding from the wall, this system gives you the flexibility to design safe, practical layouts suitable for demanding storage environments.
Product Features & Specifications of Interlocking Concrete Blocks
1.6m Allegro® Interlocking Concrete Blocks are designed for heavy-duty applications where strength, stability, and flexibility are essential. Here’s what sets them apart.
Block sizes: 1,600mm, 1,200mm, 800mm, and specialist blocks
The full block measures 1,600mm × 800mm × 800mm and weighs approximately 2,460kg. Additional sizes, including ¾ and half blocks, make it easier to stagger joints and create tidy corners.
Corners: 90° with smaller blocks
Corners are formed by combining different block sizes, allowing you to interlock rows and build strong, stable walls without bespoke corner elements.
Material density: Up to 18 kN/m³
Suitable for storing dense bulk materials such as aggregates, waste, and agricultural products.
Surcharge capacity: Up to 20 kN/m²
Walls can be engineered to withstand surcharges up to 20 kN/m², depending on wall height and material density.
Concrete strength: C40 mix
Each block is cast in a C40 mix, providing durability and strength for demanding storage and recycling environments.
Connection: Interlocking nibs and recesses
Square-top nibs fit into recesses on the block above, creating a stable, secure wall without bolts or fixings.
Design life: 100 years
The blocks are unreinforced, eliminating corrosion risk and ensuring a design life of up to 100 years.
Reinforcement cover: None required
Unreinforced construction removes the need for cover depth and reduces long-term maintenance risks.
Fire resistance: Class A1, up to 120 minutes (up to 4 hours with sealed joints)
Non-combustible concrete offers built-in fire protection. When joints are sealed with fire-rated mastic such as Sika® Hybriflex® FR, walls can achieve up to 4 hours of resistance.
Edge detail: Chamfered edges
Chamfered edges minimise visible chipping during handling and improve the appearance of finished walls.
Finish: Smooth mould finish on the front face
Front faces are mould-finished for a professional look, with back faces hand-trowelled for efficient production.
Foundation type: RC slab or existing yard slab
Blocks must be installed on a stable reinforced concrete base or existing slab. Their weight and interlocking system provide wall stability without the need for fixings.
Interlocking concrete block sizes & product range
The 1.6m Allegro® system features seven block types. This wider range of shapes makes the 1.6m Allegro® blocks the most comprehensive interlocking concrete block system we offer.
| Height (mm) | Length (mm) | Width (mm) | Weight (kg) |
|---|---|---|---|
| 800 | 1,600 | 800 | 2,450 |
| 800 | 1,200 | 800 | 1,838 |
| 800 | 800 | 800 | 1,225 |
A Partner You Can Trust
We’ve supplied precast retaining walls for over 18 years, delivering more than 1,000 projects across the UK. Contractors, farmers, and engineers come back to us because we’re straight-talking, reliable, and focused on getting projects done right.
Off-site production means less disruption, less waste, and reduced dust on site — making projects cleaner, safer, and more efficient for everyone involved.
Typical Applications
1.6m Allegro® Interlocking Concrete Blocks are ideal for fire and blast walls, storage bays, and waste & recycling facilities. Their added weight and range of shapes make them perfect for larger, more complex storage areas where higher walls and greater loads are required.
Fire & blast walls
Storage bays
Waste & Recylcing
“Thank you very much for your clear communication. With the information you provided regarding delivery and other matters, we were able to programme the actual installation of the first deliveries upon their arrival, so no time was wasted on storage or installation.”
Jason Carroll - Essex Highways
Handling & Installation of Interlocking Concrete Blocks
The larger 1.6m Allegro® blocks follow the same straightforward installation process.
- Delivered with cast-in lifting pins in the top of each block.
- Supplied with 2 × 2.5T spherical head lifting clutches for safe handling.
- Offloaded and positioned using a telehandler, forklift, or 360° excavator.
- Installed on a reinforced concrete base or yard slab — their weight and interlock provide stability without fixings.
Download the full Allegro® Blocks Media Pack
One download with everything you need — brochure, handling guide, and safety data sheets.
Everything you need to plan, specify, and install the product with confidence.
