Home > Companies > Thomas Armstrong (Concrete Blocks) Ltd > AIRTEC Foundation Block

Autoclaved Aerated Concrete (AAC) foundation blocks designed as a lightweight, speedy and cost effective alternative to traditional cavity foundation walls.

A solid AIRTEC foundation wall of 140 mm high blocks built two courses high means a faster build, shallower trenches, less waste material, no need for cavity wall ties, less mortar and eliminates any chance of collapsed cavities.


  • Solid foundation walls below dpc.
  • Thin joint construction.
  • External solid walls above dpc.
  • Support for cavity, solid and timber framed walls.
  • Support for block and beam suspended floors.

Freeze/ thaw resistant.

Related literature

The following content references this product:

Standard product features

Face size:

620 x 140 or 215 mm.

Fire resistance category:

Class A1.

Tolerance category (dimensional classification):


NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-80-50/304 Autoclaved aerated concrete (AAC) blocks
45-80-50/306 Thin joint autoclaved aerated concrete (AAC) blocks

Product specification

An important note about specifying



Thomas Armstrong (Concrete Blocks) Ltd


+44 (0)1748 810204

Product reference

[AIRTEC Foundation 140 Block]
[AIRTEC Foundation 215 Block]

Compressive strength (minimum)

[3.6 N/mm²]
530 kg/m³, 0.11 W/mK.
[7.3 N/mm²]
730 kg/m³, 0.17 W/mK.


[260 mm]
[275 mm]
[300 mm]
[350 mm]
Foundation 140 block only.

Manufacturer details

Bridge Road,
North Yorkshire, DL10 7HW
Tel +44 (0)1748 810204
Fax +44 (0)1748 813950
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NBS National BIM Library