What Importers Should Check Before Ordering EPDM Waterproof Membrane

A quotation for EPDM waterproof membrane can look complete and still leave out the details that later cause delays on site. A buyer may see thickness, width and price, but not the performance grade, jointing method, low-temperature requirement or packing arrangement. For importers, distributors and project procurement teams, those missing details matter as much as the headline specification.

This checklist is based on the applications, installation guidance and technical data currently published for Long Loong EPDM waterproof membrane. It is intended to help buyers prepare a clearer inquiry and compare offers on the same basis.

1. Start with the application, not only the thickness

Before asking for a price, explain where the membrane will be installed. Roofing, underground works, reservoirs, municipal projects, subways and tunnels do not place the same demands on a waterproofing system. A planted roof adds root-penetration concerns, while an underground structure may make future repair difficult.

Send a short project description: exposed or covered installation, horizontal or vertical surface, substrate type, expected temperature range and whether the structure is likely to move. This gives the supplier enough context to discuss a suitable grade and jointing system instead of quoting a generic roll.

2. Confirm the exact performance grade in writing

Do not accept “EPDM membrane” as the complete specification. Long Loong's current technical table lists two grades, JL1 and JL2, with different figures. At 23°C, the listed minimum tensile strength is 7.5 MPa for JL1 and 4.0 MPa for JL2. Listed breaking elongation is at least 450% for JL1 and 400% for JL2.

Low-temperature flexibility is also different: -40°C for JL1 and -30°C for JL2. Both grades are shown as having no leakage under 0.3 MPa water pressure for 30 minutes. Listed tear strength is at least 25 kN/m for JL1 and 18 kN/m for JL2.

These figures should appear in the quotation, pro forma invoice or approved technical sheet. If a project has its own test method or acceptance standard, send it before production and ask which items can be matched. Product names alone are not enough for a fair comparison.

3. Treat joints and details as part of the order

Many waterproofing problems begin at laps, corners, pipe penetrations and terminations rather than in the middle of the sheet. The published guidance for this product states a lap width of at least 50 mm and recommends firm rolling after installation. Tape ends should be sealed, and terminations may require metal fixing strips and sealed screws.

Before ordering, confirm whether compatible tape, adhesive, sealant and detail pieces are included, quoted separately or expected to be sourced locally. Mixing materials from different suppliers without verification can create compatibility risks.

4. Match the membrane to climate and substrate

Tell the supplier the lowest expected installation and service temperatures. The JL1 and JL2 low-temperature figures are not interchangeable. Also describe the substrate. The published guidance calls for a solid, level and clean base, with corners formed to a rounded or obtuse profile. It warns against installation on frozen, contaminated or excessively wet substrates.

If the site cannot meet those conditions, raise the issue early. The answer may affect surface preparation, adhesive selection, installation sequence or the proposed membrane system.

5. Review a sample and supporting documents

For a new supplier or project, request a sample that represents the proposed order. Check surface condition, thickness consistency, roll edges and how the material behaves when bent or stretched. Ask for the technical data sheet and test information relevant to the project.

For repeat orders, keep an approved reference sample and record the agreed grade, dimensions and packing. Any certificate or third-party report required by your market should be requested by name; do not assume it is automatically included.

6. Confirm packing and loading before the purchase order

Membrane performance is only one part of a bulk order. Ask for roll width, roll length, net and gross weight, core size, wrapping method, pallet arrangement and estimated loading quantity. If the goods will be unloaded manually or stored outdoors, mention that as well.

Distributors may need neutral packing or customized marks. These points should be discussed and approved before production rather than assumed after the rolls are finished.

7. Send an RFQ that can be quoted accurately

A useful inquiry normally includes destination country, application, required grade or performance values, thickness, width, roll length, total quantity, accessories, packing needs and delivery schedule. Add the destination port and any inspection or document requirements.

If some details are undecided, say so clearly. A supplier can separate confirmed items from options instead of building assumptions into the price.

A practical next step

Review the full EPDM waterproof membrane product page for the current application notes and technical table. For a project quotation or distributor inquiry, send the project location, intended use, required size and estimated quantity through the contact form or email [email protected].