Superstructure Blocks – Durox

Durox System Blockwork

The external wall is constructed from 215mm wide ‘Durox System 500’ aircrete blocks laid in a ready to use mortar provided by Tarmac. This form of construction optimises the productivity benefits associated with large format aircrete blockwork while benefitting from the excellent thermal properties of aircrete. The external insulation and render system consisting of 150mm expanded polystyrene (EPS) and thin coat render combine with the blocks to give a U-value of 0.15 W/m2K. The internal finish is a fast applied thin coat projection plaster allowing the benefits of medium thermal mass to be realized.

Whilst thermal mass is not assessed in current thermal regulations, it may be in the future. As the fabric heat loss of dwelling reduces, due to better insulated external elements, the contribution made by thermal mass becomes more significant.


The superstructure of the Code 6 home is solid wall, thin joint construction using Durox, an aircrete block from Tarmac. The dimensions used here are 620mm long x 215mm high x 215mm wide. Aircrete is a modern construction material with excellent thermal and acoustic properties. It is a versatile material which is able to provide solutions in many applications. They can halve construction time. 

Further information

Open the Durox System Brochure (pdf, 1132kb) or see more information on the Tarmac website (new window).


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Did you know?

Fact 12

Does not melt

Masonry concrete does not melt in high temperatures.  This means that there is no need for protective paints or special insulation – and finishes can be viewed just as the designer intended.

See more in Why Masonry?