Butyl Pond Liner Facts

If you are building a garden pond but have ruled out the effort and expense of making a concrete-lined pond, you are probably looking at the various types of plastic and rubber pond liner. Butyl pond liners are a popular option, and here’s some information about them to help guide you in making a decision.

Butyl rubber is the type that many of us think of when we think of rubber. First used to make tire inner tubes in 1931, butyl rubber is now used in a huge variety of applications, including adhesives, sealants, plastic cling film, lubricants, and paper, as well as pond liners. It is airtight and watertight, making it ideal for a pond liner. Pond liners made of butyl rubber are widely used in the UK. US gardeners tend to favour liners of polyethylene (PVC), which means butyl liners can be hard to find in America.

Butyl rubber pond liners are usually about 45 mm (45/1000th of an inch) thick, which is heavier than PVC liners, which are usually 20 or 30 mm. Despite this thickness, you will still need to install an underlay to protect and support the liner, which can be anything from commercially available underlays to sand to shredded old carpets. However, a butyl pond liner will prove more resistant to puncture from rocks or roots than one of PVC would.

The biggest advantages butyl liners offer are endurance and flexibility. You can expect a butyl pond liner to last 15-20 years under normal conditions, and some manufacturers will even offer a lifetime guarantee. It’s worth shopping around to find one who does. Butyl rubber is resistant to heat and UV radiation from the sun, so it does not dry out and crumble the way some other types of rubber do. It is also proof against burrowing insects and rodents who may damage other types of pond liners. Unlike PVC, butyl will not go brittle in cold weather.

Being rubber, butyl pond liners can easily be stretched, cut, and shaped to fit even oddly shaped ponds, which is not easy to do with PVC. The higher thickness does mean they weigh more and can be more difficult to lift and handle, which can be a concern if you’re doing it yourself instead of having it installed professionally.

In essence, butyl is a good middle-of-the-road choice. While other types of pond liners may fit your requirements more closely, it’s hard to go wrong with butyl, no matter what the climate, pond size or shape, or type of ground. You will, of course, have to pay more for this security than you will with PVC, but the trade-off you receive in longevity and reliability can be worth it.

Another type of rubber pond liner is EPDM, which uses a synthetic rubber instead of butyl. EPDM is slightly cheaper, and is stretchier and offers even more flexibility. Be aware, though, that a low-quality EPDM pond liner can poison the fish who live in the pond. This will not be a concern if you go with butyl.