Part 5 of 8: Installing the Liner

Using a liner allows you to be as creative as you wish. Ponds built with fish-friendly liners are easier to install and more economical than some other construction methods. In fact, constructing your pond has become a do-it-yourself project that can be accomplished over a single weekend.

It is very important to choose the right pond liner. We sell fish-friendly PondKing Membrane, a durable, highly-flexible, affordable EPDM 45mil pond liner with a 20-year warranty. Don't be tempted to buy less expensive roofing rubber. Roofing rubber may release chemicals into the water that are harmful to plants and fish. The PondKing liners we sell are designed specifically for ponds and are free of chemicals and talc. Installed properly a good quality EPDM liner could last 45 to 50 years before deterioration sets in.

Before you buy your liner, determine just how much you need. You can purchase pre-cut standard sizes or choose your own size cut from a bulk roll. Buy a piece adequate to cover the entire bottom surface-area of the pond with enough overlap to extend over the plant shelves and coping area. Because the shape of the pond is both concave and terraced, simply buying a liner equal to the overall dimensions (length and width) won’t work. Take all of the contours into consideration, including the coping shelf, plant shelves and the slope on the bottom of the pond. It may sound complicated, but it’s not.

Measure the width of the pond plus twice the depth and then the length plus twice the depth. Add at least a foot for overlap. For example, if your pond measures 10x10x2, you double the depth (4 feet) and then add one foot then add this to your length and width. Your liner should be 15x15, or 225 square feet. Always try to line your pond in one piece if possible, liners can be seamed but it is not recommended unless it is a last resort.

Another method is to use a piece of string and a measuring tape to calculate liner size. Start at the center point of one end of the pond and drape a string along the bottom, following the contours as closely as possible. Continue to drape the string across the pond from end to end. Once you've done this, measure the length of the string you used to arrive at the total length-dimension you'll need for your liner. Repeat this process for the width of the pond, measuring from side to side. If your string measures 17 by 14 feet, for example, add at least a foot and purchase a piece of liner 20 feet by 15 feet.

Before installing your liner, allow it to warm up on a paved area in the sun for a few minutes. It will be more flexible and easier to work with. Do not leave your liner out on the grass; the heat generated by the liner can kill large areas of grass. When your liner is warm, carefully unfold it and drape it loosely into the excavation, pushing it down into the skimmer niche, with an even overlap around the pond's edges. Push the liner into the planting pockets to create self-contained planters which can be filled with soil and topped with organic cat litter before water is added.

You should have a friend, or a couple of friends, help during this step -- an extra hand makes the liner much easier to maneuver. Temporarily hold the liner in place by weighting the edges with smooth stones. For larger ponds, you may need someone on each corner to help install the liner properly.

When the liner is down, set the EcoSkimmer into the lined niche. Unlike most other skimmers, the EcoSkimmer is uniquely designed to rest on top of the liner, virtually eliminating leaks. Fill behind the liner with dirt to lock the EcoSkimmer into place.

You are now ready to install decorative stone and fill your pond with water.