What Is an HDPE Pond Liner?
HDPE stands for high-density polyethylene. It is the same family of plastic used in our LDPE liners, but at a higher density, which makes for a tougher sheet that resists punctures and stretching better for its weight.
Our HDPE range is 300 grams per square metre of solid, smooth, extruded film, made from 100% virgin resin with a 5% carbon black UV stabiliser to protect it from sunlight.
Why We Quote the Weight, Not the Thickness
Almost every pond liner in the UK is sold on a nominal thickness figure in millimetres. The trouble with thickness is that you cannot easily check it, and it means different things depending on how the sheet is made.
Weight is different. Cut a square exactly 500mm by 500mm from any of our liners and put it on kitchen scales. That is a quarter of a square metre, so at 300 g/m2 it will read 75 grams. If it does not, you have not got what you paid for.
Solid and Smooth, Not Woven
Many liners sold as HDPE are actually reinforced woven sheet, where a woven mesh is sandwiched between two thin coatings. It is a perfectly good material for tarpaulins, but in a pond the weave shows as a grid pattern through clear water, cut edges can fray, and if the sheet is ever pierced water can track along the weave between the layers.
Ours is solid extruded film. No weave, a clean black finish under the water, and nothing for water to follow.
What Size Pond Liner Do I Need?
Measure your pond at its longest, widest and deepest point, then add twice the depth plus 60cm to both the length and the width. The extra 60cm gives you a 30cm overlap all the way round to anchor the edges under paving, turf or stone.
Always round up to the next size in the range. You can trim a liner but you cannot add to one. Our pond liner size calculator will work it out for you.
Do I Need Pond Underlay?
Yes. A pond liner rarely fails because the material is poor. It fails because something sharp was left underneath it, and the weight of the water presses the liner onto it until it works through.
Fitting a non-woven underlay is a condition of the 40 year guarantee on our HDPE range. Allow the same area as the liner plus around 10% for overlapping the pieces, and see our Pond Liner Underlay range.
What Does the 40 Year Guarantee Cover?
It covers UV degradation of the liner material, provided the liner is fitted over a non-woven underlay with all exposed edges covered by paving, turf or stone. Sunlight falling on bare liner is what shortens its life.
It does not cover punctures, tears, or damage caused during installation, by animals or by ground movement. This guarantee is in addition to your statutory rights.
Other Pond Liners We Stock
If HDPE is not what you are after, we also stock LDPE Pond Liners, a cost-effective and flexible option with a 25-year warranty. The full catalogue, including underlay, is on our Pond Liners page.
Why Buy Your HDPE Pond Liner From Us?
We have been supplying pond keepers across the UK for over 20 years, and this is our own branded range, specified by us rather than bought in off a shelf. That is why we can tell you the weight, the resin and the construction, and why we are happy for you to check it.
Every liner comes with a free pond building advice sheet, and our team is always happy to help you work out what you need before you order.
