Thermalite Aircrete Hi-Strength Trenchblock Tongue & Groove

Thermalite Hi-Strength Trenchblock Tongue and Groove is an alternative to the construction of cavity walls with concrete infill, engineering bricks or heavy aggregate blocks for foundations. It has a compressive strength of 7.3N/mm2, 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: 7.3 N/mm²

λ Design above dpc: 0.18 W/m.K

λ Below ground: 0.29 W/m.K

Dry Density: 730 kg/m³

Working Dimensions

Face dimensions (mm): 440 x 215

Dimensions and Weights

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

Height Length Width Dry Weight
215mm 440mm 255mm 18.1kg
215mm 440mm 275mm 19.6kg
215mm 440mm 300mm 21.3kg
215mm 440mm 355mm 25.3kg


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