Guaranteed in writing, not just on a badge.
Exactly what's covered, for how long, and how to claim — in plain English.
Last updated: 19 July 2026
The membrane guarantee
Every RPM liner we supply is guaranteed against manufacturing defects — including degradation from UV exposure, cracking, and delamination of the reinforcing scrim — for 25 years from the date of delivery, when installed on a suitable underlay in line with our installation guides. The membrane's design lifespan is longer still; the guarantee is the period we stand behind in writing.
The weld guarantee
Made-to-measure and box-welded liners leave the workshop with every factory seam pressure-tested before dispatch. Factory welds are guaranteed watertight for the same period as the membrane. If a factory seam ever fails, we repair or replace the liner.
What isn't covered
The guarantee doesn't cover damage from causes outside the material itself: punctures from tools, roots, rodents or sharp objects; installation without adequate underlay; mechanical damage after delivery; alterations or site welds carried out by others; or ponds emptied and left exposed for extended periods. Accidental damage is usually repairable — see the repair guide — and we're happy to advise even where the guarantee doesn't apply.
How to claim
Email hello@pondliner.org with your order details, photos of the issue, and a note of when it appeared. We respond within two working days. Where a defect is confirmed we will, at our choice, repair the liner, supply a replacement, or refund — and we cover carriage on valid claims.
Your statutory rights
This guarantee is offered in addition to your legal rights under the Consumer Rights Act 2015 (and the cancellation rights described in our Delivery & Returns policy). It never replaces or reduces them.
Ready for a reinforced pond liner that lasts?
RPM is the reinforced pond liner material trusted by installers across the country — 0.7 mm polymer membrane, koi-safe, 45-year lifespan.