HDPE Pond Liner UK | 0.35mm UV Resistant | 25 Year Guarantee | Fish Safe

£25.42

~~£31.78~~ £25.42

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Built to last in British gardens, this premium 0.35mm HDPE pond liner delivers professional-grade waterproofing for ponds of all shapes and sizes. Whether you're constructing a koi pond, wildlife pond, or ornamental water feature, this UV-resistant high-density polyethylene membrane provides the reliable, long-term protection your pond deserves — backed by an industry-leading 25-year UV guarantee.

HDPE Pond Liner 0.35mm: Key Facts

Material: HDPE (high-density polyethylene), UV resistant
Thickness: 0.35mm
Guarantee: 25 years
Sizes: 8 sizes, from 3m x 2.5m to 8m x 10m
Underlay: Underlay is not included; lay a geotextile underlay first.
Best for: Regular-shaped garden and fish ponds
Sold by: PondLinersco.co.uk (Express Matting Services Ltd, Burnley, Lancashire, UK)

Made from 100% virgin HDPE materials, this liner is certified fish safe and free from harmful plasticisers, making it the responsible choice for ponds housing koi, goldfish, or supporting British wildlife. Its 0.35mm thickness strikes the perfect balance between durability and flexibility, allowing it to conform to irregular pond shapes, shelves, and contours with ease during installation.

Technical Specifications

Specification	Details
Material	HDPE (High-Density Polyethylene)
Material Grade	100% Virgin Materials
Thickness	0.35mm
Colour	Black
UV Resistance	Yes — UV stabilised
Guarantee	25 years against UV damage
Fish Safe	Yes — non-toxic, aquatically safe
Stretchability	No stretch — maintains shape under pressure
Suppleness	Very supple — easy to fold and position
Applications	Koi ponds, wildlife ponds, ornamental ponds, water features
Underlay Required	Recommended (sold separately)

Key Features

✅ 0.35mm HDPE — industry-standard thickness for flexible pond liners
✅ 25-Year UV Guarantee — long-term protection against sun degradation
✅ Fish Safe & Wildlife Safe — 100% non-toxic formulation
✅ UV Stabilised — resists fading and brittleness in British weather
✅ Very Supple — easily folds around shelves, corners, and contours
✅ 100% Virgin HDPE — no recycled fillers, consistent quality throughout
✅ Pre-cut to size — ready to install straight from the pack
✅ Free UK Delivery — delivered to your door

Ideal Applications

This HDPE liner is suitable for a wide range of pond and water feature projects:

Koi Ponds — safe for koi and ornamental fish; smooth surface won't harbour harmful bacteria
Wildlife Ponds — supports frogs, newts, hedgehogs, and pond life without chemical leaching
Garden Ponds — suitable for formal and informal pond designs of all shapes
Raised Ponds — can be used with timber, stone or block raised pond structures
Stream & Bog Gardens — flexible enough for watercourse and bog garden applications
Water Features — fountains, waterfalls, and decorative water displays

Installation Tips

Size calculation: Liner size = pond length (or width) + (2 × maximum depth) + 0.6m, giving a 30cm overlap at each edge. Use our pond liner size guide if unsure.
Prepare the ground: Remove all sharp stones, roots, and debris. Use sand or a protective underlay (recommended) to prevent punctures.
Lay the liner: Drape loosely into the pond on a warm day (HDPE becomes more pliable in warmth). Work from the centre outward, pleating the liner into corners.
Fill gradually: Fill with water slowly, easing the liner into position as the weight settles it.
Trim and secure: Leave at least 300mm overlap around the edge. Trim excess and secure with edging stones or coping.

Why Choose Our HDPE Pond Liner?

With over 4,000 five-star reviews from UK pond builders, this is one of Britain's best-selling pond liners — and for good reason. The combination of UV resistance, fish-safe certification, and the 25-year guarantee makes it an outstanding investment for any pond project. Unlike cheaper PVC alternatives, HDPE doesn't contain plasticisers that can leach into water and harm aquatic life.

🐟 Fish Safe Certified | ☀️ UV Resistant | 📅 25 Year Guarantee | 🚚 Free UK Delivery

How Much Liner Do I Need?

Measure the longest length, the widest width and the deepest point of the pond, then for each direction:

Liner length = pond length + (2 x maximum depth) + 0.6m
Liner width = pond width + (2 x maximum depth) + 0.6m

The extra 0.6m gives a 30cm overlap on every edge for anchoring. Round up to the next available size; sizes work either way round.

Example: a 3m x 2m pond, 0.6m deep, needs at least 4.8m x 3.8m, so choose the 4m x 5m size.

Not sure? Use the pond liner size calculator.

HDPE Pond Liner 0.35mm: Questions Answered

What size HDPE Pond Liner 0.35mm do I need for a 3m x 2m pond?

For a 3m x 2m pond that is 0.6m deep you need at least 4.8m x 3.8m, so choose the 4m x 5m size. The formula is pond length (or width) + (2 x maximum depth) + 0.6m.

Is underlay included?

No. Underlay is sold separately. Lay a geotextile underlay over the prepared, stone-free base first, ordered in the same size as the liner, then lay the liner on top.