Bentofix^® X Geosynthetic clay liner

Bentofix^® X is a multicomponent geosynthetic clay liner (GCL) and geosynthetic clay barrier (GBR-C) from Naue. It combines a sodium bentonite core needle-punched between PP geotextile layers with an extrusion-coated PE layer permanently bonded to the woven carrier. The PE layer provides an immediate hydraulic and gas barrier (k ≤ 10⁻¹⁴ m/s, EN 14150) from installation. The bentonite core self-seals on hydration and provides the long-term sealing function. Together: two independent barriers in one product.

Naue does not publish standard list prices for Bentofix^® X products. Pricing depends on project volume, variant (X2, X5F, X10F), type (BFG, NSP), and project location. Request a project-specific quote via the contact form below or contact info@naue.com. For large containment and landfill projects, Naue provides full project engineering support including quantity optimisation.

Both are geosynthetic clay liners with sodium bentonite core and PP geotextile layers. Bentofix^® X adds an extrusion-coated PE layer to the woven carrier side. This PE layer provides three advantages:

1. immediate gas and vapour barrier from installation,
2. ion exchange protection for the bentonite in aggressive environments, and
3. higher interface friction for slope applications (X5F/X10F). Where standard Bentofix^® meets design requirements, it remains the cost-effective option.

X2 has a smooth PE coating (200 g/m²). Use for waterproofing, pond liners, below-slab applications and flat installations where slope friction is not critical. X5F has a structured PE coating (500 g/m², 0.4 mm nod height) providing ≥ 9 kPa interface friction at 20 kPa (ASTM D6243). Use for landfill side slopes and embankments requiring higher friction angles. X10F has a heavy structured PE (1,000 g/m², 0.9 mm nod height) providing ≥ 15 kPa interface friction: for the steepest slopes. All three variants are available in BFG 5300 and NSP 4000/4900 types.

A single low-permeability barrier can be compromised by ion exchange in aggressive leachate. In landfill and mining applications, calcium and magnesium ions replace sodium in the bentonite, increasing its hydraulic conductivity over time. The PE layer in Bentofix^® X prevents contact between the aggressive liquid and the bentonite, maintaining barrier integrity throughout the design life. The bentonite layer provides self-sealing if the PE layer is damaged.

One square metre of Bentofix^® X (~10 mm installed thickness) replaces up to 600 mm of compacted clay liner. This reduces excavation volumes, clay import tonnage, and transport movements significantly. The PE coating also reduces the cover soil depth required for desiccation protection compared to standard GCL.

Bentofix^® X carries CE marking, is produced under ISO 9001 and DIN 18200 third-party monitoring. Bentofix^® X2 BFG 5300 holds BBA-HAPAS certificate no. 05/4256 for waterproofing system use in the UK. ÖNORM covers X6F NSP 5300 ÖN and X10F NSP 5300 ÖN for Austrian applications. An EPD covers the Bentofix^® product family.

The Thermal Lock process integrates fibres into the PE coating, preventing delamination during handling and soil placement. Every roll is needle-detector tested across its full width before dispatch. Tensile strength: 16/16 kN/m md/cmd (X2, EN ISO 10319) and 22/22 kN/m (X5F BFG 5300). X10F NSP 4900: 25/25 kN/m. Static puncture (CBR): 2,800 N (X2/X5F) and 4,000 N (X10F NSP 4900)

All Bentofix^® X variants have a roll width of 4.85 m and a roll length of 40 m, giving 194 m² per roll. This applies to BFG 5300 and all NSP types (4000 and 4900). The 30 cm overlap zone is pre-marked on the PE surface of every roll.

CE marking, DIN 18200 third-party monitoring, ISO 9001. Testing per: EN ISO 10319 (tensile strength), EN ISO 12957-1 (internal shear strength), ASTM D6496 (peel strength), EN 16416 / ASTM D5887 (GCL hydraulic conductivity), EN 14150 (PE layer hydraulic conductivity). BBA-HAPAS certificate no. 05/4256 applies for UK use of X2 BFG 5300. ÖNORM for Austrian variants.

Yes. Naue provides engineering support including slope stability calculations, liner system design, specification preparation and installation supervision. The Naue Platform (PortalCalc) offers online tools for quantity take-off and system comparison. Contact info@naue.com or submit a project request via the contact form below.

Yes. The PE layer in Bentofix^® X provides an immediate gas-tight barrier effective against radon (Rn-222) from soil. Unlike standard GCLs, Bentofix^® X does not require bentonite hydration before achieving gas impermeability. Suitable for below-slab radon protection in residential and commercial buildings. Bentofix^® X2 BFG 5300 holds BBA-HAPAS certificate no. 05/4256 for waterproofing applications in the UK.

The PE layer creates a continuous hydraulic and gas barrier across each GCL panel. At overlap zones, the PE surfaces of adjacent panels must be bonded to maintain this continuous barrier. Bentofix^® X Tape B is a one-sided self-adhesive tape designed for PE-to-PE bonding. Without it, the PE barrier is interrupted at seams. On BFG types, bentonite impregnation provides additional overlap sealing. The overlap zone (30 cm) is pre-marked on the PE surface of every roll.