The new and patented Wi Slot Block is the choice for projects where a medium dense block is required.  Its unique slotted-design leads to a lighter unit than conventional solid blocks and better buildability.

The Wi Slot Block evolved from the frustrations and problems faced by bricklayers – the unit weights of most normal solid blocks exceed manual handling guidelines, which can result in the adoption of midi-blocks or collar-jointed walls.  Both of these options are unpopular as they involve additional work and lead to considerable extra costs and increases in the programme. However, these adverse effects can be avoided simply by using the Slot Block


Key Advantages

The Wi Slot Block system lets you build longer and stronger wall spans faster, cheaper and with fewer components.

Historically, the control of shrinkage cracking has been a major limiting factor in wall panel construction, which necessitates the use of bed joint reinforcement to enable longer spans to be constructed but incurring greater cost and build time penalties.

How the Slot Block Works

Through its innovative internally slotted design, the Wi Slot Block system uses specially engineered reduced weight, medium dense paint grade blocks to replace standard solid, medium dense blocks. The Wi Slot Block significantly enhances the mechanical and chemical bonding capacity of the mortar, for a stronger bonded joint that enables architectural designs to incorporate wider spans without the need for bed joint reinforcement.

Laying the Slot Block

Laying the slotted blocks onto a normal depth mortar bed presses the mortar up into the multiple vertical slot cavities within the block, effectively increasing the surface area of the block in contact with the mortar. This ‘stitch pattern’ mortar bond not only increases interlocked blockwork shear capacity but also reduces shrinkage cracking without the need for steel bed joint reinforcement.  This effect also stops the blocks from “floating”, making the wall much more stable whilst being constructed and “green” – ask any bricklayer who has used the Slot Block and they are likely to agree.

However, if even stronger interlinked mechanical bond is required, the Wi Slot Block system can also be installed with specially designed metal ties inserted into the vertical slots. This will further increase the lateral capacity of the block wall panel.

Health & Safety Advantages

The Wi Slot Blocks are available in 100mm, 140mm, 190mm and 215mm sizes. With the largest 215mm block weighing less than 24kg and the 22kg for the 190mm block they also offer improved health and safety benefits by removing the need for handling the heavier, standard, solid blocks.

Slot Block vs Traditional solid blocks
  • Lighter than solid blocks – helps to address manual handling issues
  • Better “grab” and less “float” on mortar bed
  • Up to 50% recycled content
  • “Green” walls are more stable than solid blocks due to better interlocking of blocks through mortar penetration into slots
  • Longer lengths can be built without the need for crack-control bedjoint reinforcement (7.5m vs 6.0m)