EPDM Rubber Pond Liners

[Nutty]

After ten years our Butyl pond liner has more holes in it than a Tetley teabag and needs replacing. Can anyone tell me whether the EPDM pond liners are all they are cracked up to be? Do they withstand dogs paddling and herons fishing? Also, when is the best time of year to replace the liner. Any tips or feedback would be much appreciated.

[King Edward]

I am currently in the process of making two ponds, one with an EPDM liner and one with a LDPM (reinforced polythene) Flexiliner. As I understand it, EPDM has generally pretty similar properties to Butyl except that it's cheaper. LDPM doesn't stretch at all like the rubber liners, but I think it's pretty tough against puncture so might resist dogs better. It's also considerably less expensive. A layer of sand/gravel over the top might also help protect the liner from above.

[michellemuffin]

we extended our koi pond last year this time using flexi liner which has been great no problems filling the pond and the dogs walk round the edges of the pond ( on top of small slabs that held the liner safe) plus we've had a hugh Heron trying his best to reach in to get our fish hes tried all round the pond to his frustration so far so good no leaks or problems when the pond was smaller we used a butyle liner but was an extortionate price for the bigger one , so far so good good luck

[dampflippers]

I don't think any livers are guaranteed against dogs!
If you are expecting dogs in then I would protect it with a layer of some sort of membrane. I think you can get underlay, so I'm sure there must be something like terram you could use.
Additionally as said- a layer of sand/gravel/clay might help.
But I wouldn't encourage dogs into any pond where you want wildlife to flourish.
Alternatively think about a puddled clay pond.

[dampflippers]

I forgot- best time- early autumn, saving as much pond weed and pond life as possible. Ideally after newt babies and tadploes have left the pond.
New dustbins, paddling pools etc are good for saving stuff into.

[Cowgirl]

Is the firestone rubber liner the same as EPDM? A fish shop told me it was thicker & better that Butyl but cheaper.

Know what you mean re dogs, mine hates water normally but after a long walk when it's hot she gets in & just stands there 'til she's cooled down. Short of putting a fence up (which I don't want to) I find it difficult to stop her as she's sneaky & wait's til your back's turned & attention elsewhere (too much border collie in her!). One day I'll be able to afford a thick rubber liner which should cut down the chance of puncture.

[NYBraby]

I moved into a new house last summer and had a fairly decent wildlife pond already there, the liner was ruined though so I undertook the excercise of replacing.

I actually did mine in November, I had seen Newts in there and was paranoid about impacting the wildlife, there were zero plants in the pond when i moved in other than a lilly. I put all the pond water into a one of those large temp koi ponds you see at fish shows and cut the grass with a saw around the edges of the pond so I could fold back the grass to pull out the liner.

I actually found 2 liners in the pond, seems someone had laid one over the other and also a carpet underlay ! I replaced with a liner bought from the below, I ordered the No10 pvc polyester reinforced pon liner, they were very helpful as well so maybe worth calling them.

Pond Liner manufacturers, Accessories,pond pumps, pond filters

I then put the water back in and scooped out lots of sludge from the old liner and added that, glad to say all my wildlife is back this year (counted over 35 Newts a few weeks back)

[Nutty]

Thanks so much for all your replies. They have been most helpful. My dogs don't go in the pond on a regular basis but, as Cowgirl says, when it is hot they make a beeline for it (visitors' dogs being the worst as they often have long nails!). Also we have a resident heron who I am sure is responsible for some of the holes.

Thanks for letting me know that the best time for repairs is Autumn.

I have been researching liners on the internet and was getting quite confused as some sites said that Butyl and EPDM were the same product (Butyl being the UK name and EPDM the US name)

However the website "Pond-Solutions" gives the following information which has clarified it a bit for me:


"Although EPDM and BUTYL RUBBER seem very similar materials, at a molecular level and in the manufacturing process they are quite different materials. Most of the supply of both these materials in this country are manufactured by no more than two extremely reliable and prestigious companies each. For EPDM I have always used a Firestone brand since that is what my local supplier stocks. For BUTYL I have always used Värnamo from Sweden, but I think both comapies make both products. For a brief description of what they consist of I will quote from Värnamo’s PR literature.

The description of the separate materials is as follows!

”Butyl: The polymer butyl (IIR - isobutylene isoprene - rubber) is an elastomer with a small number of double bonds, produced through co-polymerisation of isobutylene and isoprene.

EPDM: The polymer EPDM, ethylene-propylene rubber, is produced through co-polymerisation of ethylene, propylene and diene monomer, producing a polymer made up of saturated linear macromolecules with a paraffinic structure.”

They go on further to state that, “In addition to the base polymer, both EPDM and Butyl contain reinforcing carbon black, fillers, process chemicals, antioxidants and vulcanising agents.

After mixing the ingredients into a homogenous plastic compound, two layers of the rubber are rolled out in a calender to form a double sheet. Vulcanisation is then carried out. The long rubber molecules in the material are cross-linked through heat and pressure, creating an elastic membrane.”

In the past, it is the use of these fillers that has compromised the quality of some of the products available from more unscrupulous dealers. Hopefully these are now long gone, but to avoid dissappointment stick to a reliable manufacturer and a dealer that can tell you difference between the two products.

As far as their performance or longevity is concerned, you will find that EPDM is sold at a slightly greater thickness to a butyl product of corresponding performance or guarantee. Neither are affected by varying temperatures or the environment (sunlight, ice or rain). They are both chemically stable and always returns to its original dimensions after stretching. Although EPDM in the dark days of the past may not have been and it is not quite as malleable and stretchy as butyl. For very angular formal shapes, butyl is easier to fold into corners and around sharp bends, but for informal natural profiles, EPDM seems to iron itself to curves with the minimum of unsightly folds.

[Cowgirl]

Aah, thanks Nutty, then my pond guy was right, he showed me that the firestone (now I know that it is EPDM) is a good product. He showed me two samples & proceded to try to stretch & puncture it. Although both resisted, the EPDM kept its shape better. When you buy it ask to see some samples before you buy. The shops I've been in all have loads of these fishy shaped samples for you to examine & try to destroy!

[Red Robin]

As we are discussing pond liners, what is the stiff black material used for pre-formed pond liners please?