The Swell HDPE Pond Liner 40-Year Guarantee With Free Underlay is our best-selling pond liner. These pond liners are made from a flexible 0.35mm-thick HDPE (high density polyethylene) material that, while not quite as thick as rubber pond liners, is similarly durable. It's also UV resistant and, when paired with the standard protective underlay provided, forms a great base for a quality pond. These garden pond liners are available in a range of sizes to suit your needs. Swell UK garden pond liners are easy to fit. Their HDPE make-up makes them flexible pond liners that are well suited to a wildlife pond or sculpted garden ponds like Koi ponds. They also create a great seal, keeping pond water where it should be - in your pond! Heavy duty liners are incredibly durable and built to stand the test of time. In fact, we're so confident in the durablity of these fish pond liners, and the HDPE they're made of, that we've given them a 40-year guarantee. This 40-year guarantee covers your pond liner against damage from sunlight. It doesn't, however, cover damage from punctures so it's highly recommended that you lay down your free layer of standard protective underlay prior to installing your pond liner. The Swell HDPE Pond Liner is a best-selling choice for wildlife ponds, Koi ponds, and large garden water features. Made from durable 0.35mm HDPE (High-Density Polyethylene), it's UV-resistant, flexible, and built to last – now with a 40-year guarantee and free heavy-duty protective underlay included for added puncture resistance.Whether you're building a small garden pond or a large ornamental feature, this easy-to-install liner provides a long-lasting, watertight seal. The included underlay protects against sharp stones and roots, helping to prevent leaks and extend liner life.Available in over 20 sizes – from 2.5x2.5m to 30x40m – simply choose the right size using a Pond Liner Calculator and we’ll match the correct underlay for you.What is the Swell HDPE Pond Liner 40-Year Guarantee With Free Underlay? The most popular Swell UK pond liner, the Swell HDPE Pond Liner 40-Year...