Geomembrane — GeoTechnical Solutions

Geomembrane is a synthetic, low-permeability sheet used as a fluid barrier in civil engineering. Geomembranes are most commonly specified to contain liquids and gases in landfills, contaminated land remediation, reservoirs, ponds, tanks, canals and tunnels.

Geomembrane materials

Each polymer offers a different balance of chemical resistance, flexibility, durability and cost:

Polymer	Typical thickness	Key properties	Common UK use
HDPE	1.0–2.5 mm	Excellent chemical resistance, rigid	Landfill, mining, large reservoirs
LLDPE	1.0–2.0 mm	Flexible, good conformability	Landfill caps, irregular surfaces
PVC	0.5–1.5 mm	Flexible, easy to weld	Ponds, canals, decorative water
EPDM	1.0–2.0 mm	Highly flexible, UV-resistant	Garden ponds, green roofs
Bituminous geomembrane (BGM)	3.0–5.5 mm	Self-sealing, puncture-resistant	Tunnels, dams, hydroelectric

UK regulatory context

Geomembrane specification in the UK is most heavily regulated for landfill and contaminated land applications. The Environment Agency’s LFE 3 and CLR 11 frameworks set requirements for permeability (typically k < 1 × 10⁻¹¹ m/s for engineered barriers), seam strength and quality assurance during installation.

For water containment, the British Hydropower Association and the Reservoir Safety (Scotland) Regulations 2011 / Reservoirs Act 1975 apply, with HDPE the most common specification for reservoirs above 10,000 m³ capacity.

Installation and welding

Geomembranes are seamed by thermal fusion welding — typically dual hot-wedge welding with an air-channel for non-destructive testing. CQA (Construction Quality Assurance) procedures require pre-weld trial seams, vacuum or air-pressure leak testing of completed seams, and electrical conductivity surveys for landfill applications.

A protective non-woven geotextile (typically 500 g/m² or heavier) is normally specified above and below the geomembrane to prevent puncture from aggregate, roots or settlement.

Related ViaCon solutions

ViaCon supplies geomembranes alongside the complementary geotextiles, geocomposites and GCLs needed for full barrier systems. Explore our geotechnical solutions range. Related glossary entries: geotextile, geocomposite and geosynthetic clay liner.

Frequently asked questions about geomembrane

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