Durox Supabloc

Durox is a modern construction material, whose versatility, light weight, thermal and acoustic properties make it the ideal solution for a wide variety of applications in all types of building.

Durox can be used below ground in foundation walls, in suspended beam and block floors and in all types of internal and external walls. It provides many benefits for specifiers and contractors making it the natural choice where blockwork is specified.

Durox Supabloc combines low unit weight with high thermal insulation and acoustic performance in strengths of 3.6, 4.2, 7.3 and 8.7N/mm2.  


  • Cavity inner leaves
  • Solid External Walls
  • Solid Internal Walls
  • Separating Walls
  • Higher strength loadbearing walls
  • Solid walls below DPC
  • Cavity walls below DPC


  1. Low unit weight

    The light weight of Durox means more blocks per load, resulting in more environmentally-friendly transportation. 

  2. Fast building blocks

    Independently monitored trials have demonstrated that Durox Supabloc is over 20% faster to build with than conventional size aircrete blocks and over 30% faster than dense blocks.

  3. Easy to work

    Cutting, chasing and finishing are all straightforward and quick to achieve using standard tools.  

  4. Excellent acoustic and thermal performance

    Good U-values and Rw values, as well as Robust Details help specifiers more easily meet or exceed Code for Sustainable Homes and BREEAM requirements.

  5. Mortar Saving

    Due to fewer mortar joints, mortar savings of up to 22% can be made when compared to conventional size blocks. 

  6. Size

    At 620mm long, Durox is 40% longer than conventional size blocks, meaning they lay at 7 per m2 including mortar joints. 

Application Details

General Purpose Walling
Durox Supabloc is recommended for general-purpose walling applications including inner leaves, solid external walls, internal partitions, and solid walls below DPC. They are particularly suited for cavity and solid wall construction that require low u-values to be met. The use of Supabloc will minimise the amount of additional thermal insulation required, compared to the use of denser blocks.

Separating Walls
Durox Supabloc 4, 7, and 8 are recommended for use in separating walls including those conforming to Robust Details E-WM-6, E-WM-15, E-WM-23 and E-WM-24 as well as other key applications such as the rendered outer leaf of cavity walls, and in loadbearing situations when a 4.2N/mm2 strength block is demanded.

Loadbearing Walls
Durox Supabloc 7 and 8 are suitable for more demanding loadbearing applications, whilst retaining the characteristing low unit weight of aircrete.
Supabloc 7 is typically used in the ground floor of 3 storey housing in accordance with Approved Document A. It may also be used in separating walls including those conforming to Robust Details E-WM-6 and E-WM-15.
Like all Durox products, Supabloc 8 is produced to Category 1 manufacturing control as defined in BS 5628-1. This can provide an equivalent wall strength to that of conventional 10.4N/mm2 blocks produced to less rigorous category of manufacturing control.

Durox blocks provide excellent periods of fire resistance which can satisfy building regulations and other imposed requirements e.g. those by insurers. All Durox products conform to a fire rating of Class A1 to BS EN 13501-1: 2002.

Sound Insulation
Durox blocks may be used to provide acoustic insulation between internal rooms to meet the requirements of Part E regulations for houses and flats.

Technical Properties

Durox Supabloc (3.6n)                
Block Width (mm) 50 70* 100 115* 125* 140 200 215*
Unit weight (kg) 3.2 4.4 6.3 7.3 7.9 8.8 12.6 13.6
Laid weight (kg/m2) 28 39 55 64 69 77 111 120


Durox Supabloc 4 (4.2n)                
Block Width (mm) - - 100 - - 140* - -
Unit weight (kg) - - 8.7 - - 12.1 - -
Laid weight (kg/m2) - - 72 - - 101 - -


Durox Supabloc 7 (7.3n)                
Block Width (mm) - - 100 115* - 140 200* 215*
Unit weight (kg) - - 9.3 10.7 - 13.1 18.6 20.1
Laid weight (kg/m2) - - 77 88 - 107 153 165


Durox Supabloc 8 (8.7N)**                
Block Width (mm) - - 100 - - 140* - -
Unit weight (kg) - - 9.9 - - 13.8 - -
Laid weight (kg/m2) - - 80 - - 113 - -


* Denotes a made to order product. Please note availaibility may be dependent on order quantity and delivery location. Other dimensions and strengths may be available on request.

** Durox Supabloc 10 has been re-named Durox Supabloc 8. There has been no technical specification changes to the product and therefore can be used exactly as before.

Durox Supabloc 8 is a high strength aircrete block produced at 8.7 N/mm² compressive strength and meeting Category I manufacturing control, Durox Supabloc 8 can provide an equivalent wall strength to 10.4 N/mm² blocks produced to Category II manufacturing control. This is due to the different safety factors applied to Category I & II.

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