We often get asked whether you can overlap pond liners. It seems like a simple question, but in the pond world, overlapping can mean a host of things. Below we have covered some of the most common queries related to overlapping pond liners.
The simple answer to this is yes, for the most part!
Almost all pond liners are already joined together from smaller widths, either by us or at the manufacturer’s factory. For PVC and SealEco pond liners, we use heat and compression welding to achieve this, whereas with Elevate we use a cold-applied tape system (for larger lakes). No matter which way we join the pond liner, chemical bonds are created through the layers, so this becomes the strongest part.
It is possible to connect pond liners where you have a waterfall or stream entering your pond, an L-shaped pond or where you want to extend your pond. We recommend using the same liner material for the different elements. Don’t forget, you will need to overlap the pond liner in order to join it, so ensure you have enough.
Using an edge of the pond liner for fixing is one of the most popular choices, both for natural shaped ponds and box welded liners.
For a natural pond, usually, the excess material is either buried into an anchor trench or laid with heavy rocks or slabs on top to hold it in place.
For a box welded liner, we add an overlap to the walls that can be flipped over the top of the pond and then secured to hold the liner in place.
Unless you are fixing to a vertical wall, we recommend using this overlap method and not cutting your liner to the exact size of the pond. You can find out more about this here.
It can be very tempting when replacing your pond liner to just lay the new liner directly over the top of the old liner. We don’t recommend this.
If the original pond liner has or develops any holes or cuts that are not at the lowest point, these will provide an entry point for water to get between the two layers. This water cannot drain through the lower layer so will build-up, causing the overlapping pond liner to bubble up.
Removing the old liner is also a good opportunity to do some ground maintenance, for example reforming any steps in your pond that may have been compressed over time.
Yes, it is possible to overlay your pond liner with sand, gravel, rocks or other materials. In order to protect the pond liner from any damage from these, we would recommend placing a layer of geotextile underlay over your pond liner before these are added. Our 300gsm underlay is black in colour, so would not show through any gaps in the material.
We hope the above can help you understand what is possible when overlapping pond liners, but if you have any further queries, don’t hesitate to get in touch.