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Pond Liners Guide
Here at Pondkeeper we specialize in Garden Ponds and we have helped many thousands of customers to install their projects. We know that many of you will be considering your first water garden project and we want to help you every step of the way.Why do I need a pond liner?
The first stage of any pond project is excavation (digging a hole!). The next process is to cover the excavation with a pond liner. A pond liner is simply a waterproof fabric that keeps the pond water in the hole. A pond liner is essential as without it the water would simply seep into the ground.Pond Liner Characteristics
Most pond liners are created by joining together (or ‘seaming’) sheets of fabric together. This is true for all liners of a very large size. These joins are made in the factory and are very strong. A similar process is used for all liners regardless of type.LDPE Pond Liners - Introducing Flexiliner
We have sold all the different types of pond liners over the years. We speak every day with our customers so know what works and what doesn’t. Over time we have come to believe that LDPE offer the best value. This belief led to the creation of our famous Flexiliner Pond Liner product which is exclusive to pondkeeper. LDPE is an acronym for Low Density Polyethylene. This is the base fabric which is created via an ultra-tight weaving process. This woven fabric is then laminated on both sides with a UV resistant coating which strengthens the liner and allows long-term outdoor use.Benefits of LDPE Liner We like Flexiliner for the following reasons: Highly economical – the best value pond lining. Tearproof – if the liner is damaged during installation a small puncture will not ‘run’ and create a bigger problem. Light in weight so easy to move into position. Highly flexible so easy to bed down into corners and tricky shapes. Available in a massive range of over 90 sizes. Proven to remain watertight for many years – this confidence reflected in the long guarantees we provide with this product. PVC Pond Liner
The next step up (price wise) is PVC pond lining. We sell 0.5mm thickness PVC as we have found this to be the best weight for this fabric. PVC has a slight stretch to the fabric that LDPE doesn’t – however this elasticity comes at a cost (liner is not tearproof). PVC is a much heavier fabric. Our PVC comes from top brands such as Gordon Low Pond Liners, Oase Pond Liners and more recently we have introduced the Blagdon Pond Lining System which includes a top quality PVC Liner with matching Underlay in one pack.Rubber Pond Liners
Both EPDM Pond Liners and Butyl Pond Liners are synthetic rubber liners. Butyl has a higher natural rubber content and is highly regarded by professional pond builders. Unfortunately, the polymer used in creating this pond lining is in high demand across other product sectors (eg, car tyres) – this has resulted in the product becoming prohibitively expensive. We still offer our customers Butyl rubber as many projects include this item during the specification process. However, the pond market in general has moved towards EPDM Rubber. Although slightly different in it’s manufactured chemical make-up with EPDM you have a product which looks and feels almost identical yet is substantially cheaper to produce and purchase. Fortunately EPDM actually offers better characteristics than Butyl. If you are looking for reassurance then our thickest and heaviest rubber pond liners are made by Firestone.Firestone EPDM Pond Liners are 1.02mm thick and are designed to last. However, it is worth noting that this fabric though more puncture resistant is harder to move into position when addressing the contours of your pond. Rubber lining is something of a commodity product. Prices shift due to market forces as the polymers used in their construction are required by a host of competing industries. In 2012 Firestone was the best value for money but recent increases mean that we go into 2013 with EPDM as the value rubber solution. Pond Liner Underlay
Please do not neglect the need for lining your pond with underlay before your introduce the liner. The purpose of an underlay is to protect the liner from pressures both above and below the surface. They provide a cushioned surface to prevent sharp stones puncturing the liner when the weight of the pond water comes to bear on the fabric. (In even the smallest ponds remember that 1000 litres of water weighs 1 tonne – in a large pond to the liner has to take the weight of many tonnes).
Also your pond is at risk from danger from below as roots from garden plants can continue to grow unseen under the pond and push through the liner at a later date. A good underlay acts as a barrier to deter such problems.
Here at pondkeeper we offer our basic underlay which is highly popular and low-cost. This is a ‘finishing’ underlay – a light fabric that takes the edge off sharp stones and grit. It is recommended for small ponds where conditions are relatively smooth – ie, a clay/soil base.
In larger projects or where conditions are poor (stoney ground) then our pond fleece pond liner underlay is popular. This is a far thicker 200gsm fabric which offers much better protection.
If you have particularly poor ground with an unlevel base then consider first lining with sand. Compact the sand until the surface is smooth and then use pond fleece underlay to protect the sides and base. The sides of your pond should still be smooth and even but come under less pressure than the pond base area.
Some customers are surprised to find that pond liner underlay is not supplied as a single sheet. But this is typical in the pond market as underlay needs to be supplied in so many different sizes to match the liners but it does not need to be in one piece. We supply our underlay in 2x5m and 2x8m pieces.