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EPDM or HDPE pond liner

Updated: 22 October 2026

You have seen EPDM or butyl on a specialist site, and HDPE on an amazon.co.uk title, and the two are being sold as if they were one product with different branding. An EPDM or HDPE pond liner choice is a material choice. Pond-grade rubber from those shops is not the polyethylene in this comparison, a bullet that says rubber does not convert HDPE, and roofing EPDM is not automatically safe for fish. The twelve sheets, with GBP prices, are on the [pond liner comparison](/hub/garden-ponds/pond-liner). Peter F. compared those listings with the shop pages named below, and did not lab-test a roll. A qualifying purchase can earn us a commission at no extra cost to you.

You have seen EPDM or butyl on a specialist site, and HDPE on an amazon.co.uk title, and the two are being sold as if they were one product with different branding. An EPDM or HDPE pond liner choice is a material choice.

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What the specialist shops mean by EPDM

Water Garden publishes PVC at 0.5 mm, SealEco GreenSeal EPDM at 0.75 mm or 1.00 mm, and butyl at 0.75 mm. Those are that shop's catalogue figures, not terms for the sheets here. The Royal Horticultural Society still describes butyl as the popular flexible choice, with a stated life of 25 to 50 years or more. No British Standard in the sources sets a minimum domestic thickness. Hold 0.75 mm next to a 0.1 mm title that says heavy duty. How to size the hole first is on the pond liner buying guide. None of the twelve is 0.75 mm EPDM.

What these listings mean by HDPE and LDPE

Most rows say HDPE, from 0.1 mm to 0.5 mm. WARM&LOVE, kanghelong, and MuAnWei are 0.1 mm. PondKraft states tri-laminate LDPE, 0.35 mm, and at least 200 g/m², at £28.99. A live line calls it a substitute for butyl. That is the maker's sentence, and 0.35 mm is not 0.75 mm EPDM. GARDENIX states 200 gsm and names no polymer. Do not invent a millimetre for that weight. Storystore's material line says HDPE, and a later bullet says rubber. The rubber word does not make the sheet EPDM. Which size you can reconcile is on best pond liner.

Fish-safe is a sentence until a certificate is printed

Almost every listing has a fish sentence, and no certificate is printed. A star rating is not a UK safety approval. Liners Online warns that some roofing-grade EPDM can carry additives that pond-grade EPDM does not, and says to buy a product labelled for ponds. That is one seller's warning, not a test of every roofing roll. In England, a closed garden pond can sit outside the fish-permit rules under 0.4 hectares if it is not fished, not linked to other waters, and in the curtilage of a home. GOV.UK's ILFA list does not give koi its own line.

Fold, or stretch

Specialist pages sell EPDM and butyl as sheets you can mould over shelves. Reviews of this polyethylene set describe something stiffer: no stretch, a tarpaulin feel, and cracking when a sheet is folded. That is enough to stop a butyl stretch method on 0.1 mm film. Stay with this set for a container, a barrel, or a small hole when you have measured the rectangle, you will buy fleece separately, and you accept that 0.35 mm tri-laminate is the clearest stated sheet here. PondKraft is that LDPE row. It is not EPDM. Leave when you want 0.75 mm or 1.00 mm pond-grade rubber, or a life wording that belongs to butyl. The sequence is on how to fit a pond liner.

Common questions

What is in this comparison, if it is not EPDM?
HDPE and LDPE garden sheets from 0.1 mm to 0.5 mm, PondKraft tri-laminate LDPE at 0.35 mm and at least 200 g/m², and one 1 m square sold as 200 gsm with no polymer name. There is no butyl ASIN and no EPDM ASIN. Prices in the snapshot run from about £5.99 to £59.99.
What thickness do specialist shops publish for EPDM, butyl, and PVC?
Water Garden publishes 0.5 mm PVC, GreenSeal EPDM at 0.75 mm and 1.00 mm, and butyl at 0.75 mm. The RHS describes butyl and PVC without those millimetre lines. None of those figures is a British Standard. They are the numbers to hold next to a 0.1 mm or 0.5 mm amazon.co.uk title.
Does a bullet that says rubber make an HDPE sheet into EPDM?
No. Storystore prints HDPE and, in another bullet, rubber. The material line is the one that names the polymer. EPDM and butyl are absent from this set. Preformed and underlay on a title do not put a shell or a fleece in the box unless the box line lists them.
Is roofing EPDM safe for fish?
Do not assume it is. Liners Online warns that some roofing grades carry additives that pond-grade EPDM does not, and says to buy a product labelled for ponds. That is a seller's warning, not a test of every roofing roll. A black offcut is not identified by colour.
Do these listings prove fish safety?
They assert it. Bullets say harmless or preferred for koi. No certificate is printed, and the star line is not an approval. Satisfactory quality under the Consumer Rights Act 2015 is a duty on the seller. It is not a fish-toxicity test.
When is polyethylene enough, and when should I leave this set?
Polyethylene is enough for a container, a barrel, or a small hole when you have added depth and overlap, you will use separate underlay, and you can accept folds instead of stretch. Leave when you want 0.75 mm or 1.00 mm pond-grade EPDM or butyl. PondKraft at 0.35 mm is the clearest sheet inside the set, and it is still LDPE.
Is LDPE on the Tezhiie and PondKraft rows the same specification?
No. PondKraft states tri-laminate LDPE at 0.35 mm and at least 200 g/m², 4 m by 4 m, at £28.99. Tezhiie states LDPE at 20 mil / 0.5 mm on a 4 m by 5 m title, at £59.99, while the dimensions print 0.5 cm, and saved texts include a split and stuck welds. Do not buy one because the other said LDPE.

Related pages

Sources

Public UK sources for this comparison. Listings and prices were taken from amazon.co.uk on 21 October 2026.

  1. RHS: How to make a new pond (retrieved 21 October 2026)
  2. Freshwater Habitats Trust: frequently asked questions (retrieved 21 October 2026)
  3. Planning Portal: permissions for a garden pond (retrieved 21 October 2026)
  4. Keeping and Introduction of Fish (England and River Esk Catchment Area) Regulations 2015 (retrieved 21 October 2026)
  5. GOV.UK: introduce or keep non-native fish, lobsters and crayfish (retrieved 21 October 2026)
  6. GOV.UK: great crested newts, protection, surveys and licences (retrieved 21 October 2026)
  7. Water Garden: pond liner materials (retrieved 21 October 2026)
  8. Consumer Rights Act 2015, section 9 (retrieved 21 October 2026)