The liner, otherwise known as the 'tarp', ensures the watertightness of the pond and is therefore essential. The choice of a pond liner is not easy when faced with the multitude of references available on the market. Let's try to see it more clearly...
Interests of the pond liner
- When creating a pond, the liner allows for unequalled freedom of shape.
- Generally less expensive than a preformed shell, the first prices remain accessible to most budgets.
- It also ensures a superior longevity and is not affected by frost and bad weather.
However, a geotextile felt should be slipped under the liner to avoid possible damage caused by roots or rodents.
Choosing a pond liner
The choice of liner depends on many criteria such as price, size and material.
Liners can be found in the form of rolls varying from 3 to 8 m in width and 25 to 60 m in length. If the dimensions of the liner are smaller than the size of the pond, it will be necessary to glue the strips together.
The 'first price' liners are generally made of PVC. There are three thicknesses: (0.5/0.8/1 mm). If you don't want to drain and repair your pond regularly, forget the first one! PVC liners are quite difficult to install because of the folds that inexorably form. PVC also poses some environmental concerns as it is difficult to recycle and toxic substances can migrate into the water. It is also a little sensitive to high temperatures, with a risk of softening for 'first price' references. However, a good quality PVC liner can last for 10 years.
Composite liners are appreciated for their extreme resistance and lightness. They are made of a thermo-bonded polypropylene sheet and 0.55mm polyolefin copolymers. Very innovative, these tarpaulins have an excellent flexibility and ensure an easy installation. They are resistant to cold and heat, as well as to traction and punching. These recyclable tarpaulins are more expensive (about 8 €/m²) than PVC liners, but they have practically nothing but advantages and are for the most part guaranteed for 25 years.
EPDM liners are recommended and used by professionals because they are very resistant, and come in long lengths and widths to create large ponds in any weather. They are available in thicknesses ranging from 1 to 1.14 mm.
A very good flexibility, a very high stretching capacity, a resistance to punching and to climatic hazards are added to these technical assets. This highly elastic synthetic rubber is easy to lay and does not wrinkle.
The lifespan of such a liner is at least 20 years. It is recyclable and compatible with aquatic life.