PVC Coated Gabion

A PVC coated gabion is a wire mesh container filled with stone or rock, where the wire is protected by a factory-applied PVC coating.

This creates a dual-layer defense: the inner galvanized or Galfan wire resists corrosion, while the outer PVC coating (0.4–0.6 mm thick) acts as a physical barrier.

This makes them suitable for coastal areas, industrial sites with chemical exposure, wastewater facilities, and urban environments where de-icing salts accelerate metal degradation. The system works as both a structural retaining element and a permeable drainage medium.

Technical Principles

The core wire is high-tensile steel (2.0–4.0 mm diameter) first coated with zinc or zinc-aluminum through hot-dip galvanizing. Then a PVC layer is applied, increasing the finished wire diameter to 3.0–5.0 mm.

The PVC formulation includes UV stabilizers and plasticizers that keep the coating flexible from -30°C to +60°C. Color pigments (typically green, gray, or black) are mixed into the PVC during manufacturing, not painted on afterward.

The mesh can be either woven (hexagonal twisted) or welded (rectangular grid). Welded mesh offers higher strength initially. Woven mesh is more flexible and won’t unravel completely if a wire breaks.

Specification Notes

Common failure points to address:

Coating problems: The PVC coating can peel, crack, or show gaps. Require salt spray testing (ASTM B117) with no rust after 1,000+ hours. Check that coating thickness is uniform and properly bonded to the wire.

UV damage: Sunlight degrades PVC over time. For exposed installations, specify UV-stabilized formulations with documented testing (ASTM G154). Ask for proof that UV inhibitors are included in the compound.

Base wire quality: Request mill certificates confirming the core wire meets ASTM A975 or EN 10223-3 standards for tensile strength. Verify the galvanizing weight meets minimum requirements (typically 245 g/m²).

Cut edge corrosion: Exposed wire at cut edges is where rust usually starts. Quality manufacturers seal all cut ends with PVC paste or heat-shrink caps. Your specification should explicitly require this edge treatment.

Connection strength: For welded mesh, welds should maintain at least 80% of the wire’s strength. For woven mesh, verify the twist pattern prevents the mesh from distorting when filled with stone.

Ask manufacturers for batch testing records and traceability documentation linking delivered gabions to material certifications. In coastal or chemical environments, specify Galfan core with PVC coating rather than standard galvanized, as Galfan provides better chloride resistance.