Seam welding: fusion (wedge) & extrusion

Seams are the most critical part of any liner. We weld with our own equipment, and every welding day starts with trial welds that are tested before production welding begins.

Fusion (automatic wedge) welding

An automatic wedge welder heats the two overlapping sheets and presses them together as it travels along the seam. It is used for the long field seams between geomembrane panels.

Extrusion welding

An extrusion welder lays a bead of molten HDPE over the prepared overlap. We use extrusion welding for detail work: corners, pipe penetrations, patches and repairs. Hot air guns are used to tack the sheets in place before the extrusion weld.

Controlling weld quality

  • Trial welds before production welding each day, tested in peel and shear with our tensiometer
  • Welding by manufacturer-trained welding technicians
  • Non-destructive testing of seams by vacuum box and spark testing
  • Seam records kept for the as-built drawings and handover documentation

Have a lining project coming up?

Send us the application, approximate area, liner specification and site location, and we'll come back to you with a scope and price.