Lightweight walling offers real sustainability advantages 


We strive to advance the use of sustainable building materials to enrich people’s lives and benefit the planet by developing and producing low carbon footprint products using recycled waste materials.

We use 100% recycled polystyrene. This reduces the more than 70 000 tons of polystyrene which currently ends up in South African landfills per year and offers the following sustainable benefits:

  • Polystyrene is used as an effective aggregate replacement in lightweight concrete for building much needed homes
  • Conversion of existing buildings into student residences, apartments, entry level housing and hotels is on the increase, with more and more developers looking to re-use or re-purpose existing building stock in key locations. In many instances, the existing foundations require significant investment to cater for the load of traditional brick and mortar walls onto the existing infrastructure and, although lightweight walls such as drywall are popular in commercial developments, they lack the robustness in residential refurbishments. CemteQ’s lightweight walling systems offer 70-75% weight saving over conventional materials and deliver on thermal, acoustic, robustness and fire rating requirements.
  • The collection of polystyrene provides an income for dozens of people

Our lightweight concrete products offer excellent insulating qualities with long-term savings in energy consumption over the lifecycles of buildings.

The carbon footprint of CemteQ’s recycled polystyrene concrete

The carbon footprint of the cementitious blend used in the CemteQ lightweight block is 421kg of CO2 per ton based on the use of 60% GGBFS and 40% milled clinker vs 980kg of CO2 per ton for CEM1 in the South African context. This translates into a carbon footprint for the cementitious component of 208kg of CO2 per m3 of CemteQ product.  

An assumption has been made that the carbon footprint for the aggregate used in our product is net zero based on the fact that the product is either transported to our processing plant or to landfill.

The carbon footprint of clay brick (assuming a similar carbon footprint in SA)

In the UK, it is claimed that a typical cubic metre of brick has embodied emissions of around 357kg of CO₂ per ton. This comes from extracting the raw material from quarries, processing it, shaping it into raw bricks and firing them in a kiln at a very high temperature. Using a typical weight of clay brick at 1700kg/ m3, the CO2 per m3 would be 607kg CO2 per m3.

The carbon footprint of conventional concrete (source Wikipedia)

The CO2 produced for the manufacture of a low strength concrete is estimated at 410 kg/ m3 (~180 kg/tonne @ density of 2.3 g/cm) (reduced to 290 kg/m with 30% fly ash replacement of cement).

In summary, it can be concluded that the annual CO2 offsetting rate varies from 21.77 kg CO2/tree to 31.5 kg CO2/tree. To compensate for 1 ton of CO2, 31 to 46 trees are needed. Based on an average of 26.6 kg CO2/tree, the CemteQ 650D product offsets 15 more trees than clay brick and 7.6 trees more than an average traditional concrete.  

 CO2/m3Trees per m3
CemteQ Concrete (650D)2087.8
Clay Brick (1700D)60722.8
Traditional Concrete (2400D)41015.4