The three main materials
Almost all pond liners are made from one of three materials: PVC (polyvinyl chloride), EPDM (ethylene propylene diene monomer) or butyl rubber. Each has distinct characteristics.
PVC
- Weldable — the only material suitable for box welding
- Flexible and easy to handle
- Resistant to UV, chemicals and abrasion
- Available in 0.75mm and 1.0mm thicknesses
EPDM
- Very flexible, even at low temperatures
- Good UV and ozone resistance
- Typically heavier than PVC
- Available in limited thicknesses
- Available in 0.75mm and 1.0mm thicknesses
Butyl rubber
- Extremely flexible and puncture-resistant
- Good for very cold climates
- Heavier and more expensive than PVC or EPDM
- Less common today than in previous decades
- Available in 0.75mm and 1.0mm thicknesses
Our recommendation
For a box-welded liner, both PVC and Rubber are great options. Durable, fish-safe, weldable to precise tolerances and backed by a 25-year guarantee. If you are comparing a box-welded boxwelded liner against a flat sheet EPDM liner, the comparison is less about material and more about construction method.