H+H's Celcon Blocks High Strength Grade (7.3N/mm2) and Super Strength Grade (8.7N/mm2) are used principally where higher compressive strengths are required such as in the foundations and lower storeys of three storey buildings, piers under high vertical loads and in multi-storey buildings.
Our higher strength grade blocks were re-named from Hi-Seven to High Strength and Hi-Ten to Super Strength in 2011. Apart from the name, there has been no technical specification changes to the product and it can be used in exactly the same way and in the same applications as before*.