Thermalite Aircrete Trenchblock

Thermalite Trenchblock is an alternative to the construction of cavity walls with concrete infill, engineering bricks or heavy aggregate blocks for foundations. It is available as Hi-Strength Trenchblock (with compressive strength of 7.3N/mm2) and with tongue and groove joints and handholds for easy handling.


  • Improves thermal performance
  • Available in standard or with tongue and groove joints and handholds
  • Can be used in thin joint masonry, saving time and money  
  • Removes the need to mortar perp ends
  • Moisture resistance

Key Data

Compressive Strength: 3.6 N/mm²

λ Design above dpc: 0.15 W/m.K

λ Below ground: 0.24 W/m.K

Dry Density: 600 kg/m³

Working Dimensions

Face dimensions (mm): 440 x 215, 440 x 140

Dimensions and Weights

Block thicknesses and weights at equilibrium density (for 440 x 215mm)

Height Length Width Dry Weight
215mm 440mm 255mm 14.9kg
215mm 440mm 275mm 16.1kg
215mm 440mm 300mm 17.5kg
215mm 440mm 355mm 20.8kg


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Thermalite Guide

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