Galvanised Woven Gabion Baskets - Class A Galvanised & PVC Coated

Gabion basket installation requires no specialist plant or equipment and is suited to semi-skilled and unskilled labour under competent supervision. The critical requirements are correct geotextile placement before basket assembly, proper basket erection and lacing, correct rock infill size and compaction sequence, diaphragm panel installation in baskets longer than 1.5m, and correct lid lacing to complete the structural connection between basket courses. Incorrectly laced connections between adjacent baskets and between basket courses are the primary cause of gabion structure failure - correct lacing technique must be demonstrated to all installation personnel before work begins.

1. Foundation Preparation and Geotextile - Excavate and trim the foundation to the specified formation level. Compact the foundation surface. Place the non-woven geotextile separation layer over the foundation and up the full back face of the gabion structure before any basket is positioned. Overlap geotextile lengths by a minimum of 300mm in the direction of water flow. The geotextile must be continuous behind and beneath the full gabion structure without gaps or unprotected sections - gaps in the geotextile are the most common cause of fines migration and long-term deterioration of gabion retaining structures.

2. Basket Assembly and Erection - Unfold gabion baskets from the flat-packed supply format. Erect by folding up the four side panels and two end panels to form the box shape. All vertical panel edges of adjacent baskets must be laced together using 2.2mm binding wire with a continuous lacing stitch at maximum 150mm centres, alternating between single and double loops at every connection point. A single loop only at each connection point is insufficient and will open under load. Position assembled empty baskets in their final location and lace horizontally adjacent baskets together at all common edges before any filling begins.

3. Diaphragm Panels - For all baskets longer than 1.5m, install internal diaphragm panels at 1.0m centres along the basket length before filling. Lace diaphragm panels to the basket base and front face before filling begins. Diaphragms prevent face bulging under the lateral pressure of rock infill and the gravity load of subsequent basket courses. Omitting diaphragms in long baskets causes characteristic face bulging that reduces the effective gravity mass of the structure and the visual quality of the finished wall face.

4. Rock Infill Placement - Fill baskets in three layers, hand-placing all outer face stones carefully to achieve a tight, even face appearance and maximise fill density at the basket face. Machine filling of the basket interior is acceptable once the outer face layer is hand-placed and stable. Limit drop height of infill material to a maximum of 1m to prevent basket deformation during filling. Do not overfill - the rock surface must be level with or slightly below the basket top to allow the lid to close and lace flat. Compact each layer before placing the next to minimise post-construction settlement of the basket fill.

5. Lid Lacing and Subsequent Courses - Fold the wire mesh lid down flat onto the filled basket and lace to all four sides using 2.2mm binding wire at maximum 150mm centres, alternating single and double loops. Lace adjacent basket lids together across the full width of the structure. The lid lacing is a structural connection - inadequate lid lacing allows the upper basket course to separate from the course below under lateral load. Place the next course of empty baskets directly on top of the laced lids and repeat the assembly, filling, and lacing sequence for each course until the full wall height is achieved.

6. River and Channel Applications - For river bank protection and channel lining, install basket courses and mattresses working from the downstream end upstream so that each upper panel overlaps the lower in the direction of flow. Anchor all free edges and mattress perimeters using steel pegs driven through the mesh into the bank or bed at maximum 1m centres. For permanently submerged applications in corrosive river environments, specify PVC coated gabion baskets and mattresses. Place a non-woven geotextile separation layer beneath all river mattresses over erodible bed material before mattress placement.