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The Thermalite Aircrete Trenchblock Tongue & Groove – 300mm is a purpose-designed foundation block engineered to simplify below-ground construction while delivering strong thermal performance and reliable strength. Manufactured from lightweight Thermalite aircrete, this trench block offers excellent insulation properties alongside easy handling on site.
Integrated tongue & groove ends allow blocks to interlock securely without mortaring perp joints, while built-in handholds help speed up installation and reduce manual strain.
Designed for foundation and below-ground construction
300mm wide trench block suitable for narrower foundation walls
Tongue & groove ends remove the need for mortared perp joints
Lightweight aircrete construction for easier handling
Integrated handholds improve on-site productivity
Good thermal performance compared to traditional dense trench blocks
Trench wall foundations
Sub-DPC blockwork
Retaining and foundation walls
Projects requiring improved thermal efficiency below ground
Block Type: Aircrete Trench Block
Material: Aircrete (cellular concrete)
Face Size (L × H): 440 × 215 mm
Thickness: 300 mm
Compressive Strength: 3.6 N/mm²
Thermal Conductivity: Approx. 0.24 W/m·K (below ground)
Configuration: Tongue & Groove with handholds
Pack Size: 20 blocks
Standards: Manufactured to BS EN 771-4
We supply site-ready foundation blocks selected for ease of installation and dependable performance. The Thermalite 300mm tongue & groove trench block helps reduce build time, improve thermal efficiency, and deliver consistent results below ground.
