| Applicable product specification | Confirm that the proposed HDPE geomembrane meets the project specification and the applicable edition of GRI-GM13, where specified. | Product data sheet, declared standard and edition, and a clause-by-clause compliance matrix. | Standards and project requirements can differ; a general claim of compliance does not establish that every required property is covered. |
| Thickness and thickness tolerance | Specify nominal thickness by application. Common project selections include 1.0 mm, 1.5 mm, and 2.0 mm; the project documents should define the required tolerance and measurement basis. | Recent test results for nominal and minimum average thickness, plus roll labels identifying thickness and lot. | Thickness affects material quantity, handling, installation, and the design properties required for the project. |
| Resin density and material identification | Compare the declared resin density with the applicable product specification; GRI-GM13 includes a density requirement for HDPE geomembranes. | Batch-specific test reports and resin traceability records. Density testing is commonly performed using ASTM D1505 or an applicable equivalent method. | Traceability and test evidence help confirm that supplied material matches the approved product specification. |
| Tensile properties | Check yield and break properties against the required specification for the selected thickness and test method. | Independent or quality-control test results stating specimen type, test method, thickness, and results. ASTM D6693 is commonly used for tensile properties of geomembranes. | Tensile results support evaluation of the sheet’s mechanical properties during handling and service. |
| Carbon black content and dispersion | For black HDPE geomembrane, verify carbon black content and dispersion against the applicable specification rather than relying on color alone. | Test reports identifying the method and results; ASTM D4218 is used for carbon black content and ASTM D5596 for dispersion evaluation. | These properties are relevant to material consistency and resistance to ultraviolet exposure. |
| Oxidative induction time (OIT) | Review standard OIT or high-pressure OIT requirements, as applicable, against the project specification and the selected test method. | Test reports stating the OIT method, conditioning, and results. ASTM D3895 and ASTM D5885 are commonly used for standard and high-pressure OIT testing, respectively. | OIT testing evaluates antioxidant response; results should be interpreted within the specified method and project requirements. |
| Roll dimensions and packaging | Confirm roll width, length, thickness, core, and packaging format against site access, handling equipment, and installation plans. Dimensions are product- and order-specific. | Approved roll schedule, packing list format, sample roll label, and written confirmation of dimensional tolerances. | Accurate roll planning helps reduce handling difficulties, unnecessary seams, and delivery discrepancies. |
| Seam testing and installation support | Require a documented trial-weld and field seam quality-control plan appropriate to the project and joining method. | Welding procedures, technician qualifications where required, trial-weld records, and seam test procedures. ASTM D6392 covers destructive seam testing for nonreinforced geomembranes. | Field seam performance depends on installation conditions and workmanship as well as the sheet material. |
| Quality management and lot traceability | Expect a documented quality system and a clear link between production lots, test records, roll labels, and shipping documents. | Quality-system certificate with scope and validity confirmed, inspection plan, lot-specific certificates of analysis, and traceability samples. | Traceability makes it easier to investigate nonconformities and verify delivered rolls against approved submittals. |
| Independent inspection and testing | Agree in advance on sampling frequency, test methods, acceptance criteria, and whether testing will be performed by an independent laboratory. | Inspection and test plan, laboratory credentials, sample chain-of-custody records, and reports tied to specific production lots. | Pre-agreed verification reduces ambiguity during production, shipment, and material acceptance. |
| Export documentation and delivery planning | Confirm the required shipping documents, delivery term, destination port, packaging, and realistic production and transit schedule in the purchase contract. | Pro forma invoice, packing list, certificate-of-origin arrangements if required, shipping plan, and written schedule milestones. | Clear logistics requirements help buyers manage customs, site readiness, and delivery risks. |
| Warranty and claims process | Review the written warranty’s scope, exclusions, duration, notice requirements, and remedy; do not treat warranty length as a substitute for technical verification. | Contract warranty, claims procedure, response contacts, and documented process for handling nonconforming material. | Written terms clarify the parties’ responsibilities if a product or delivery issue arises. |