When it comes to pond construction, there are certain methods that anybody can perfect, but there are also some that should be left to the professionals.
The easiest and least expensive method for any DIY-enthusiast is to use a flexible liner. You can buy a DIY pool construction kit from most companies that specialize in fish pond supplies, although some of them prefer to only supply the liner, leaving the decision of what else to buy to you.
The most popular and most successful pond liner in the USA is made of EPDM (an ethylene-propylene polymer – ethylene-propylene-diene-monomer), and is usually a 45-mil thickness. It is not difficult to install and you don’t need any building skills at all. It is also a relatively simple matter to join pieces of the material together, which means that you can build a pond of any size or shape.
There are other flexible liners in the form of PVC (polyvinyl-chloride) and polyethylene, but while these are cheaper than EPDM, they are also not as long lasting, and will be more likely to puncture.
Whichever type of liner you choose to use, it is good practice to install some type of underlay between the earth and the liner. This is seen as a preventive measure that will help to avoid puncturing and tearing. Geotextile materials are ideal, because they can be cut to size and simply placed over the surface of the excavation. Sand works well on the pond floor, but for obvious reasons it doesn’t work for walls.
While you need a pond liner to be reasonably thick, the thicker the liner, the more difficult it will be to avoid forming folds and creases. Don’t be too concerned. If you look at photographs of people installing liners you will see that there are always folds. Some will straighten out when you fill the pond with water, while you can just neatly tuck other extraneous bits of liner into nooks and crannies, or fold them under a pond edging.
Using a preformed pond is also a simple matter, although these are normally relatively small. So it will depend on the size and depth pond you want. Basically all you have to do is to dig a hole and set the preformed pond inside it; backfill and sort out some type of surround or planting.
Digging any type of pond can be hard work, and quite time consuming, particularly if the soil in your garden is hard or full of clay. You will also need to be sure that the upper level of the pond is level, particularly if you are using a preformed liner. This means you will need a spirit level or a water level to check your levels. The thing is that water finds its own level, and so if one end of the pond is higher than the other, you will notice this when the pond is full of water.
Of course there is nothing to stop you using any of the other pool construction methods for a DIY garden pond. These include concrete cast on site, as well as building ponds using bricks or blocks laid with mortar.
