THERMALITE 3.6N TRENCHBLOCK T&G 355MM (440mmx215mm) (15)

The Thermalite Aircrete Trenchblock Tongue & Groove – 355mm is a purpose-designed foundation block engineered to make below-ground construction faster, more thermally efficient, and easier to install. Manufactured from lightweight Thermalite aircrete, this trench block delivers excellent thermal performance alongside reliable strength for modern foundation and trench walling applications.

The integrated tongue and groove ends allow blocks to interlock securely without mortaring perp joints, while built-in handholds improve handling and speed up installation on site.

Key Features

• Designed for foundation and below-ground construction

• 355mm wide trench block ideal for cavity wall foundations

• Tongue & groove ends remove the need for mortared perp joints

• Lightweight aircrete construction for easier handling

• Integrated handholds to reduce labour strain and improve productivity

• Good thermal performance compared with traditional dense trench blocks

Typical Applications

• Trench wall foundations

• Sub-DPC blockwork

• Retaining and foundation walls

• Projects requiring improved thermal efficiency below ground

Technical Specification

• Block Type: Aircrete Trench Block

• Material: Aircrete (cellular concrete)

• Face Size (L × H): 440 × 215 mm

• Thickness: 355 mm

• Compressive Strength: 3.6 N/mm²

• Thermal Conductivity: Approx. 0.24 W/m·K (below ground)

• Configuration: Tongue & Groove with handholds

• Pack Size: 15 blocks

• Standards: Manufactured to BS EN 771-4

Why Buy From Us

We supply site-ready foundation blocks selected for ease of installation and dependable performance. The Thermalite 355mm tongue and groove trench block helps reduce build time, improve thermal efficiency, and deliver consistent results below ground.