How to Install your Pond Liner

How to Install your Pond Liner

The following instructions have been written to provide guidance when installing your pond.

For more complex designs, if you have questions about any of the steps or for any other help please call us on 01225 632444 and we will be happy to help you.

  1. Excavate the pond to the correct shape and size. Any stones or roots must be removed and the base, sides and shelves compacted firmly. Ideally, the sides should slope fairly steeply (3 in 1 drop) although in soft soils a more gradual slope will suffice. The sides should be no steeper than 45o to ensure a stable bank. If you want a vertical bank, this should be built up with blocks or bricks to stabilise the bank. Ensure that the edges of the pond are level.

    Calculate the amount of liner and underlay required using our measure and calculate your pond liner
  2. If the ground conditions are still stony cover the base and sides with fine sand. Install a layer of protective matting underlay over the base and sides to protect the pond liner.
  3. Place the folded liner in the middle of the base and carefully unfold it, moving it into place as you proceed. With PVC in particular, it is wise to choose a warm sunny day, as the liner will be more supple.
  4. Stretch the liner slightly and hold the liner edges in place with large stones or other weights. It may be useful to get somebody else to help at this stage. The middle of the liner should sag onto the base. Overstretching the liner will reduce the strength of the material, and should be avoided. Make sure that the weights holding the edge of the liner cannot fall into the pond and damage the liner.
  5. Start filling the liner with water. As the pond fills, and the liner stretches, gradually ease off the weights around the pond edge. Make use of the liners elasticity to even out as many creases as possible.
  6. When the pond is full, check that the edges are level and add or remove soil as necessary. The excess liner can be trimmed back with sharp scissors. An overlap of approximately 150mm is usually adequate if paving is the preferred edging. Other edgings may require more overlap (learn more about fixing options).
  7. Especially in the corners, where there are more folds, check that no part of the liner drops below the edge of the pond. Seepage at such a point makes it impossible to keep the pond full.
  8. The pond should always be kept full so that no part of the liner is exposed to UV from direct sunlight.


For more information on building a pond, see our How-To guides.

Back to blog