Gordon Low Rubber Pond Liner – EPDM 0.75mm

Gordon Low Greenseal EPDM Rubber Pond Liner – 0.75mm

Gordon Low Greenseal 0.75mm EPDM is a flexible rubber membrane for lining garden ponds, wildlife ponds and water features. Choose a sheet that covers the entire pond profile, with sufficient material for the sides, shelves and finished edge. The dimensions in the selector describe the flat sheet supplied; they are not the dimensions of the pond that can be built from it.

This listing is for the selected liner only. Underlay, pipe fittings, drain seals, adhesives and edging materials are separate purchases. Our options include compact 2m x 2m and 2m x 2.5m sheets as well as larger sizes, including 4m x 5.5m. Select the exact dimensions for your project and check the whole installation plan before cutting the material.

What is Greenseal EPDM?

Greenseal is a synthetic rubber pond liner from SealEco, supplied through Gordon Low. The manufacturer identifies it as fish-safe and describes a vulcanised material designed to remain elastic and resist weathering. It can follow a carefully prepared pond profile without the rigid shape limitations of a preformed shell. Its flexibility is useful around curves, but the excavation must still provide proper support.

EPDM and butyl can look and feel similar, but they are different materials. This product is 0.75mm EPDM, not butyl and not the thicker 1mm EPDM option. If you are comparing quotations, check the material, thickness, actual sheet dimensions and whether underlay is included. Similar names or the same headline price do not necessarily describe the same package.

Work out the liner size

Start with the maximum length, maximum width and maximum depth of the proposed pond. A useful initial estimate adds twice the depth and the required edging allowance to each surface dimension. For example, a pond 2m long, 1m wide and 0.5m deep would need approximately 3.6m x 2.6m of liner if you allow 0.3m beyond each opposing edge. Your fixing detail may require more material.

That calculation is a planning aid. Before ordering, measure the finished excavation with a flexible tape laid down one side, across the base and up the other side, then include the edge detail. Repeat across the other direction and account for shelves, slopes and irregular shapes. A shelf is part of the profile, and the distance following the ground matters more than the water surface area alone.

A 2m x 2m sheet should therefore never be assumed to make a 2m x 2m pond. Water depth and edge anchoring use a significant portion of the material. Choose the next suitable sheet size that covers both measured requirements, rather than trying to stretch a smaller piece into place. Do not trim the final allowance until filling and settlement are complete.

Prepare and protect the excavation

Remove sharp stones, roots and building waste, and deal with unstable soil or unsupported pockets before installing any membrane. The liner provides waterproofing; it does not make an unstable wall structurally sound. Think about access for installation, the weight of large sheets and where heavy rocks or paving will be placed later.

Lay suitable protective underlay over the surfaces that will contact the membrane. Our Gordon Low white geotextile underlay is one option to compare. Follow its instructions for overlaps and coverage. Underlay helps protect the liner but does not replace good excavation preparation or guarantee protection against every sharp object.

Check the planned edges and any penetrations at this stage. Bottom drains, skimmers and pipe connections should have a sealing arrangement suitable for EPDM. Install them according to their own instructions and the liner supplier’s guidance. Keep tools, grit and sharp offcuts away from the working surface, and protect the membrane when placing equipment or entering the excavation.

Laying and filling the pond

Unfold the liner carefully and position it so there is enough material around the entire perimeter. Let it settle into the pond shape, arranging folds without pulling the rubber taut across corners or hollow areas. Avoid dragging a large sheet across rough paving. Having help available makes it easier to position the material without damaging it or losing the allowance on one side.

Fill gradually and watch the membrane move into contact with the prepared base and sides. Adjust loose folds while it is practical to do so, keeping hands and tools clear of loaded areas. Check the level and the remaining edge allowance as the water rises. Finish the edging only after the liner has settled and the intended water level has been confirmed.

Joining, repairs and future maintenance

Where possible, plan around a suitable single sheet. A project requiring a seam needs the correct EPDM preparation and joining system, used under the specified conditions. Do not assume a PVC adhesive, roofing product or general-purpose sealant is appropriate simply because it sticks to a test offcut. The waterproof joint has to remain reliable when installed and submerged.

If the water level later drops, check waterfalls, pipework, fittings and exposed edges before concluding that the membrane is damaged. Locate the actual leak before buying a repair product. Keep the liner label and purchase details with the pond records, and retain any manufacturer guarantee information. Guarantee coverage depends on the product and terms; accidental punctures and installation damage should not be assumed to be covered.

Compare other lining options

For a thicker rubber option, see our Gordon Low 1mm EPDM pond liner. For a smaller project with a tighter material budget, compare Gordon Low 0.5mm PVC pond liner. Consider the complete installation, including underlay and fittings, rather than comparing thickness or price in isolation.

Order a made-to-size 0.75mm EPDM sheet

Cannot find a suitable standard pack? Enter the finished flat-sheet dimensions below for a made-to-size liner price. Use our pond liner size calculator as a starting point, then check the actual pond profile and edging allowance before ordering. Enter the sheet size, not the pond’s surface size.

Custom sheets usually take 2–3 weeks. They are made to your measurements and may include factory-made joins; they are not box-weld liners. Choose optional white 150gsm underlay or black 250gsm heavy-duty underlay. The calculator recommends packs with overlap allowances and adds these as a separate basket item.