Materials For A Garden Pond

Rigid moulded liners made from vacuum-formed plastic are the cheapest and they usually come with built-in shelves. They are relatively easy to install, and many people like them because the shape is predetermined, but they are fairly short¬lived. PVC-based and rubberized compounds are available; these are slightly more expensive, but are longer lasting. Moulded fibreglass pre-formed liners are the longest lasting of all, but are not so easy to find, and are more expensive when you do.

These are basically lengths of waterproof sheeting, enabling you to build a pond of any shape or size. More planning is required, and calculating the amount of liner you need is not always easy. Lined ponds are ideal for informal schemes, since the sheeting will fit most shapes and contours, albeit with varying amounts of creasing. Many raised ponds, which at first appear to be constructed entirely of bricks and cement, are actually lined inside. The best reliability comes with rubber sheeting known as butyl, but PVC and LDPE (low-density polyethylene) sheets are also to be recommended. Buy lengths with a guarantee of 20 years or more. Polythene is common at the cheaper end of the scale, but it lacks pliability and becomes brittle after prolonged exposure to sunlight, so is best avoided. Finally there are 'geotextile' liners, which are rubber-based liners impregnated with sodium bentonite. These are self-healing liners -if they sustain a minor puncture, the bentonite will plug the hole.