Pond Liners

About

Pond Liners & Underlay for Every Garden Pond Every pond that lasts starts with the right liner. We've spent over 20 years at AllPondSolutions helping people line everything from small wildlife pools to large koi and ornamental ponds, and ours are built to go the distance — flexible enough to mould to any shape, tough enough to hold water for decades. Pick a lightweight 0.3mm LDPE liner with a 25-year warranty for most garden ponds, or a heavy-duty 300gsm HDPE liner guaranteed for 40 years when you're building big and building once. Pair either with a protective underlay for a watertight base you can rely on. Browse the full range below — all with fast, free UK delivery. .aps-buying-guide{margin-top:1.25em;padding:0.9em 1.1em;border:1px solid rgba(0,0,0,0.15);border-radius:8px;background:rgba(0,0,0,0.02);}.aps-buying-guide summary{cursor:pointer;font-weight:600;}.aps-buying-guide[open] summary{margin-bottom:0.6em;} Buying guide: how to choose & size your pond liner Get the size right first. Measure your pond's longest length, widest width and deepest point, then add twice the depth to both the length and the width so the liner reaches up and over the edges with enough spare to tuck under your edging. It's always better to order a little large and trim the excess than to come up short once the pond is filled and the liner has settled — a liner that's tight in one corner can't be stretched later. Our pond liner size calculator works it out for you in seconds. LDPE or HDPE? LDPE (0.3mm, 25-year warranty) is the flexible, cost-effective choice for most garden and wildlife ponds. HDPE (a true 300gsm, 40-year warranty) is a thicker, heavier film for large or permanent ponds you want to build once and forget. Lay either over a non-woven underlay — it shields the liner from stones and roots, and it's required for the warranty to apply.