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Quality Assurance

Product and workmanship guaranteed 100% for quality assurance

For a dam good job ...

Our process, product selection, deployment methodology, attention to detail, and stringent testing ensures workmanship and guarantee a quality job. We take pride in our work, having assembled a team of highly trained professional installers. We follow international best practice guidelines and New Zealand health and safety requirements. We constantly seek improvement so that we can deliver the best solutions cost effectively to our clients.

At each site our process has regular checkpoints to achieve a high level of quality assurance:

  • Subgrade site inspection and sign-off;
  • Daily on-site calibration of welders;
  • Computer designed panel placement ensuring efficient product use;
  • Testing all panel seams and repairing if needed;
  • Providing a workmanship warranty;
  • A 20 year manufacturer supplied material warranty.


Unlike many other systems, HDPE geomembranes are tested to ensure the installation meets recognized quality assurance standards, and at the completion of each job I.S. Dam Lining Ltd provides – in accordance with Dairy NZ guidelines:

  • Certificates from the geomembrane manufacturer confirming full QA compliance with the relevant approved GRI test specification for the batch from which the installed geomembrane was supplied.
  • Site records, including installer’s subgrade acceptance, panel numbering and placement, trial welds and seam tests, and other supporting quality assurance documentation.
  • Material warranty for up to 20 years from the geomembrane supplier, which has been pre-approved by the manufacturer for the stated period.
  • Installation (workmanship) warranty from the geomembrane installer for a minimum period of 5 years.
  • Certification by the installer that they have completed their work to the drawing, specifications and any other relevant documents. This certification usually takes the form of a signed Producer Statement.