How to achieve a best-fit pond liner for Koi ponds
May
15
Written by:
Monday, May 15, 2017
Today, the most commonly used pond liner for formal-shaped Koi ponds of a square, rectangular, circular or 'L'-shape is a box-welded pond liner. In fact, any shape vertically sided Koi pond designs can be accommodated. Box-welded pond liners are an aesthetically more pleasing alternative to installing a flexible 2-D pond liner.
Why a box-welded liner for Koi ponds?
For Koi ponds your objective should always be to achieve a lining with as few folds and creases as possible, as these will trap debris and are difficult to keep clean. Fish faeces can accumulate in these folds and produce pathogens that will affect the quality of your water and health of fish. This is especially true for Koi, which are particularly susceptible to impurities in their water. 
Butyl and Epalyn (an EPDM synthetic rubber pond liner) pond liners are durable and can be readily manipulated into many shapes and sizes including circular-shaped ponds with vertical sides. The main advantage to lining Koi ponds in this way is that there are no unsightly folds once installed. The seams of the liner are welded together for maximum strength.
Synthetic rubber pond liners are resistant to temperature extremes and UV light, therefore won’t perish or become brittle with age. They are also highly resistant to compressive loads and rodent attack. Epalyn pond liners offer a slightly greater tensile and tear strength than butyl rubber - it is a cheaper liner to manufacture too so a preferred choice.
Ordering a box-welded pond liner
A box welded liner is cut and welded to the exact shape of your pond so when ordering this type of lining it is wise to dig your pond first and take exact dimensions (length x width x depth - dimension for a lip must be added to the design too) to pass on to the supplier who will then cut and weld the pond liner into the exact shape required so that it 'fits like a glove' into your Koi pond.
A tip when planning your Koi pond build - to achieve the depth you require, vertical drops can be stepped in stages. Sloping bottoms can be incorporated so long as they are consistent. The advantage of vertical sides is that dead organic matter won’t get trapped and will fall to the bottom where it can be vacuumed up or where it will slide down towards a bottom drain.
All box-welded pond liners ordered from Russetts Developments Ltd (RDL) will include a lip onto which edging material is laid to secure the liner in place.
Our team at RDL have many years’ experience fabricating box-welded pond liners, which are cut and welded to the exact shape of your pond. We are always available to give advice on what can be achieved. Some examples of our box-welded pond liners can be seen on our website. The EPDM material we use is Epalyn EP, which is particularly suited to the vulcanisation process used to bond the elements of a liner together and carries a lifetime guarantee on orders of up to 100m2.
For a quote or more details on our bespoke pond liner service, please contact us at 0870 770 2800 or visit our website for information on our products and services. You can also send your design sketches and dimensions to us via email at info@russetts.co.uk.
Here are photographs of a project RDL recently completed. The design brief was to install a pond liner without any folds or imperfections. The customer initially considered a flat sheet pond liner but realised that the creasing would be substantial in a shallow pond. After the hole was dug and the ground cleared, 400g/m2 Geotextile protective underlay was installed to level the area making it look flat and smooth as well as to protect the pond liner during and after installation.
1.2mm Flagon TPO pond liner was used for this project, which was completely fabricated on site using hot air machines to create a smooth finish in keeping with the formal pond design.
