The two materials we use
All our box-welded pond liners are manufactured in EPDM (ethylene propylene diene monomer) or Butyl rubber. Both are available in 0.75mm standard grade and 1.0mm heavy duty, both carry a 25-year guarantee, and both are safe for fish and aquatic plants.
EPDM
- Excellent UV and ozone resistance
- Highly flexible, even at low temperatures
- Lightweight and easy to handle on site
- Available in 0.75mm standard and 1.0mm heavy duty
Butyl rubber
- Extremely flexible and puncture-resistant
- Performs particularly well in very cold climates
- Long track record in pond construction
- Available in 0.75mm standard and 1.0mm heavy duty
Which should you choose?
For the vast majority of ponds — garden ponds, koi ponds, natural swimming pools and raised features — either material performs equally well. The 0.75mm grade suits most domestic installations; the 1.0mm heavy duty is recommended for koi ponds, larger builds, or anywhere additional robustness is valued.
If you are unsure which is right for your project, just mention it in your quote request and we will recommend based on your pond type, size and location. If you are comparing a box-welded liner against a flat sheet liner, the more important consideration is construction method, not material.
For application-specific material recommendations, see our koi pond liner page (where we recommend 1.0mm heavy duty) and our natural swimming pool liner page.