1 mm EPDM pond liner, from 5.6 to 35 m²

Name: EPDM pond liner
SKU: d32b4de2-808f-432e-826e-e56bbd2c06ad
Price: 103.9 EUR
Availability: InStock

The summary

Thickness: 1 mm of elastomer, which withstands a pump placed on the bottom and routine maintenance.
Material: EPDM, an elastomer that stretches, whereas a plastic film wrinkles.
Which size to order: the formula is simple, and it starts from the depth as much as from the base.
Sizes: ten cuts, from 5.6 m² to 35 m², in black.
How to choose: between elastomer and thin film, the shape of the pond and the length of the installation decide.
How it arrives: rolled up, and heavy from the larger sizes upwards.

1 mm waterproofing elastomer, in ten sizes up to 35 m²

The EPDM pond liner is a black waterproofing elastomer, 1 mm thick, offered in ten sizes from 5.6 to 35 m². Unlike a plastic film that creases, EPDM stretches and moulds to a freely dug base, with shelves and a deep pit. It suits a garden pond, a buffer tank or an aquaponic fish tank.

A pond liner is chosen on three points, and the first is the material. This one is made of EPDM, a synthetic rubber, cut at a thickness of 1 mm and supplied on a black roll. The other two are the surface area, which is worked out from the dimensions of the pond, and the thickness, which determines how well the liner stands up under a pump and during maintenance work.

🧪 An elastomer that stretches

An elastomer stretches and then returns: laid in a hole dug with a spade, it settles into the corners and presses against the wall under the weight of the water, without you having to make any folds. A thermoplastic film, on the other hand, does not recover after stretching: it folds, and each fold concentrates the mechanical stresses.

That is why you lay an elastomer in a free-form pond and a film in a flat-bottomed tank. The practical consequence shows on site: with EPDM, you dig whatever shape you like, including shelves for marginal plants and a deeper pit where the fish will overwinter, and the liner follows. With a film, it is the liner that imposes its geometry on the pond.

📏 Working out the surface area you need

For a rectangular pond of length L, width w and depth D, in metres, with an overlap margin of 0.30 m on each edge:

liner length = L + 2 D + 0.60, and liner width = w + 2 D + 0.60.

A pond measuring 2 m by 1.5 m and 0.60 m deep therefore needs 3.80 m by 3.30 m. The depth counts twice, once for each side wall, and it is the most common oversight. For a free-form shape, measure the greatest length and the greatest width, then apply the same formula. Shelves add nothing to the calculation, because the maximum depth already covers the combined height of their steps.

The ten sizes cover ponds of very different dimensions, and the same formula can be read in reverse to see what each size lets you line. For a pond 0.50 m deep, the 2.8 by 2 m size leaves a base of about 1.20 m by 0.40 m, which suits a small reserve. The 4.2 by 3 m size already covers a pond of 2.60 m by 1.40 m at that depth. At a depth of 0.80 m, the largest, at 7 by 5 m, lines a pond of 4.80 m by 2.80 m. Two areas come in two forms, 16.8 m² as 5.6 by 3 m or 4.2 by 4 m, and 21 m² as 7 by 3 m or 4.2 by 5 m: choose the one whose proportions match those of your pond, to avoid having to trim off an entire strip on one side.

What goes in at the same time as the liner

The day of installation is the only time the base is accessible. An outdoor circulation pump and an air pump fitted at that point, before filling, find their place and the route for their cable without you having to step into a full pond.

Unrolling the large formats with several people

The 1 mm EPDM weighs a little over 1 kg per square metre, so the 16.8 m² package exceeds 20 kg and the 35 m² one reaches 43 kg. Carry the roll to the edge of the hole rather than dragging it, because a stone or a root will cut the liner as soon as you slide it across the ground. Then unroll it with two or three people, in soft-soled shoes, and never walk on it in treaded soles that hold on to gravel.

🪨 From the bottom to the edges

The liner lasts as long as the base it rests on stays clean. Once you have dug the hole, remove the stones and roots, firm down the soil, then spread a few centimetres of sand over any stony areas before laying a geotextile, which receives the liner. Also allow, all around the pond, for a small trench about twenty centimetres deep where the edge will be folded back and then covered with soil or stones: the edge is then held above the water level without you having to stretch the liner. The steps follow in this order, from the base to the edges.

Clean the bottom

Remove the stones, trim the roots and firm the soil down, because anything sticking out will eventually mark the liner.

Lay a geotextile

It sits between the soil and the liner, and absorbs what the cleaning has left behind.

Unroll without stretching

The liner is laid loose, then the weight of the water presses it against the bottom and sides.

Fill up, then switch off

Fill with water first, adjust the edges next, and only then trim off the excess.

🐟 A watertight fish tank

In an aquaponic system, this liner is the wall that separates the water from the soil, and it stays in permanent contact with a living environment. Its black colour absorbs light instead of reflecting it and blends into the pond once filled; against the filamentous algae that proliferate in summer, the shade of floating plants remains the main lever. Its thickness lets it withstand the feet of a pump that you place on the bottom, the passage of a net and routine maintenance without being cut.

As it is laid once and for all, choose a generous size: any surplus can be trimmed after filling, whereas a liner that is too short cannot be lengthened without a join. For a fish pond, the guide to koi carp in aquaponics gives the volume and depth to allow for before you work out your liner size.

📐 Angles and folds

On a pond with straight sides, the excess liner gathers in the corners. Rather than leaving several small creases, which you would struggle to flatten, gather it into a single large fold per corner, laid flat against the wall, then hold it in place while filling: the pressure of the water then presses it against the geotextile. On a free-form pond, the elasticity of the EPDM absorbs most of the curves, and only the sharpest ledges need a fold made by hand. Fill slowly, adjusting the liner as the water level rises, so that no air pocket is left trapped behind a wall.

Once the pond is full, leave the liner to settle for a day before trimming off the excess with a utility knife, leaving about twenty centimetres beyond the final water level. The edge is then folded down into the trench or under a coping of flat stones, which protects it from the sun, footsteps and garden tools. If your pond serves as the tank for an aquaponic system, run the pump outlet and the water return over the liner rather than through it: you then have no penetration to seal below the water level.

Technical specifications

The essentials

Material: EPDMEthylene propylene diene monomer, an elastomer: it stretches and springs back, rather than creasing.
Thickness: 1 mmA thickness that supports a pump placed on the bottom and the passage of a landing net.
Available surfaces: 5.6 to 35 m²Work out your own before choosing: the depth of the pond counts twice in each dimension.
Shade: BlackIt absorbs light rather than reflecting it, and blends into the pond once filled with water.
Cutting: With a craft knife, once filled with waterTrim off the excess once the water has pressed the liner into place, never before.
Packaging: RollStore flat and out of the sun until the day of installation, to avoid creases.

To budget for separately

Geotextile: A protective felt under the linerIt withstands the stones and roots left behind when the bottom was cleaned.
Weighting the edges: Flat stones, gravel or a wooden frameThe edges hold once the pond is filled and the liner has settled.

In the box

1 black EPDM liner, 1 mm thick, supplied on a roll, in the size selected.

Material, thickness, colour and available sizes: product data sheet, consulted on 20/09/2026. The surface area formula is arithmetical and applies to a pond with vertical walls.

EPDM or HDPE, two ways of waterproofing a pond

Two materials, two thicknesses, two ways of laying them.

Torn between these two liners? One is a thick rubber that fits into a hollow, the other a thin film that lines a flat base. Three questions are enough to decide.

	Thickness (mm)	Largest surface area available (m²)	Stretches to fit a hollowed-out shape	Price
Recommended EPDM pond linerYour choice	1 mm	35 m²	Yes	103,90 €
HDPE pond linerYour choice	0,2 mm	9 m²	No	21,90 €

EPDM pond linerRecommended

Thickness (mm)1 mm

Largest surface area available (m²)35 m²

Stretches to fit a hollowed-out shapeYes

HDPE pond liner

Thickness (mm)0,2 mm

Largest surface area available (m²)9 m²

Stretches to fit a hollowed-out shapeNo

Thicknesses, available sizes and material types: product data sheets, recorded on 20/09/2026.

Estimate your
delivery time

A long, heavy roll in the larger sizes. Plan on being two people to move it to the pond. The exact charges are shown at the basket once the address has been entered.

Frequently asked questions

10 questions

6 key questions, 10 in the detailed view

What size of liner should you order?

Do you really need a geotextile underneath?

Can it be installed in cold weather?

How do you trim off the excess?

Is it safe for the fish?

Can a puncture be repaired?

Can two liners be joined together?

Is it suitable for an aquaponic grow bed?

How should it be stored before installation?

Does it need maintenance?

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EPDM pond liner

The summary