Rubber pond liners are one of the easiest and cheapest way to build a reliable, high quality pond. They are flexible, tough and built to last many years when installed under the ground. There are two types of rubber liners that have become popular for building ponds or other liquid containment situations. These are EPDM and Butyl rubber liners.
An Ethylene Propylene Diene Monomer, or EPDM pond liner is another popular choice among pond builders. Although EPDM pond liners can't be welded like butyl liners, the seams can be taped with heavy-duty butyl tape, making the seams fully waterproof. That being said, there is a reasonable chance that when purchasing an EPDM pond liner that you will be able to find one piece large enough to line your entire pond without any seams since EPDM is available in many different sizes and shapes. Because of this, it often takes less experience and equipment to effectively line a pond with EPDM since no welding is required. However, because EPDM liners are flat sheets, when conforming to a 3D shape like a pond, there will naturally be folds or pleats present. These can often be hidden with plants, rocks or other features, but nevertheless, this could be considered a disadvantage over a box-welded butyl liner, which would have no folds whatsoever.
Isobutylene Isoprene Rubber, nicknamed BUTYL for short, is a synthetic rubber that is quite common in everyday products that would require a waterproof or airtight bladder. Examples of products that make use of Butyl include tire inner tubes, ball air bladders, caulks and sealants, cling wrap and even chewing gum. One of the advantages of Butyl when used as a pond liner is the ease at which smaller, flat sheets can be welded together to create virtually any 3D shape, a process known as box-welding.
Often times, a butyl rubber pond liner can be purchased box-welded into commonly sized 3D pond shapes such as square, rectangular or L shaped. Box-welded liners are very easy to install, and often contain no folds or bunches due to their custom made shape. Some manufacturers will even create box-welded liners made to order based on a set of plans or a template. However, before you get too excited, it's important to point out that most pre-welded liners are relatively simple shapes. If you plan on building a pond in a very irregular shape, or with lots of shelves and ledges, it may be quite difficult to find a pre-welded liner. In this case, welding a butyl liner on site (which may be costly), or using an EPDM liner might be a better choice.
While not technically made of rubber, there is another material worth noting that welds very well. This material is polypropylene, and we happen to sell it in a number of preformed box shapes (see the link on the right). Custom shapes are available as well. The main advantage of buying a preformed box welded liner is the cost savings; you'll spend much less money buying a preformed shape rather than hiring a contractor to custom weld the liner on site. Our polypropylene is a great product - it's highly UV resistant, strong, light and very safe for fish, plants and humans. In addition, it is guaranteed not to leak any harmful chemicals into your water. In fact, it's approved for human consumption applications like fish farming, gardening, or even for storing drinking water. To learn more and see prices for various sizes, please see the liner in our store.
Once a pond is completed, it would obviously be quite costly and time consuming to remove and replace the pond liner with another. It is for this reason that choosing a reputable liner manufacturer up front could save you some headaches down the road. When choosing a rubber pond liner, it is important to choose one that is specifically being sold into the pond market, and not into a different industry such as roofing. Although the two industries may seem similar, roofing membranes may contain certain chemicals that could be dangerous to fish and other life in your pond.