4 Steps to Replacing a Pond Liner

Once you’ve settled on replacement, you’re looking at a good chunk of work, so it’s wise to plan to make the most of your effort. Think about the damage - do you have a good idea of what caused it? What steps can you take to avoid similar problems in the future? Consider installing barriers for errant wildlife, removing nearby trees with invading roots, or even developing a strict policy to keep the skimmer away from Uncle Fred. Careful planning can be the difference between repeat performances and a permanent solution.

Choose your Liner

Next, you’ll need to decide which material makes the most sense for you and your pond. PVC may appear to be the best choice if budget is a concern, but that type of liner rarely lasts more than ten years, even when installed and protected precisely according to instructions. EPDM rubber is not only highly vulnerable to punctures, but it’s heavy and unwieldy during installation. If your pond is even moderately large, dragging the liner over the ground is hard to avoid, so you’ll need to arrange for a small crowd of willing helpers.


Less durable liners like PVC and EPDM always require underlayments to perform correctly. Underlayments are essentially a cushion meant to protect the liner from - you guessed it: punctures and tears. They’re available in different thicknesses and are generally made from some sort of non-woven material like polypropylene. The material may be prone to shifting during installation, but no area should be left exposed, so overlaps are usually necessary. The perimeter of the pond (such as an anchor trench) should also be covered by underlayment. These extra steps add expense and time to your relining project, but they’re necessary if you want the liner to last.

Over the long term, an extremely durable lining like BTL’s AquaArmor makes sense - it’s both lighter and more flexible than HDPE and highly resistant to punctures, tears, and friction damage. It’s highly impervious to UV radiation and available in warranties up to 40 years. AquaArmor is a once-and-done liner, solid and reliable well into your golden years.

Geo Ribbon

Finally, there’s a relatively new and exciting add-on to consider. Many pond liner manufacturers and installers are beginning to offer an optional overlayment, sometimes called Geo or Geo Ribbon. Years of experience have taught pond professionals that any form of physical damage (from deer, kids with rocks, mechanical equipment, UV degradation, etc.) is much more likely to occur on the upper edges of the liner, not at the bottom of the pond. To offer additional protection in these vulnerable spots, you have the option to add a “ribbon” of geotextile overlayment along the upper edges of the liner. This overlayment is less slippery than typical liners and provides an extra degree of protection against accidents. It also provides a bit of extra grip, so plants and decorative substrates like river rock are less likely to slide out of place. Geo is not required, but it can add convenience and a relatively cheap form of practical insurance.

Measuring and Ordering

When you’ve decided on your liner choice(s), it’s time to measure and place your order. Remember that your liner should have the fewest seams possible to minimize the potential for leaks, so plan out how you intend to lay the liner accordingly. You also need to account for the depth of the pond and add several inches on each side to allow for anchoring the liner. If you have to add underlayment, you should plan on purchasing one at least as large as your liner and allow for overlaps. Then there’s tape, glue, and anything else required for installation.

BTL’s pond liners are available in single panels up to 150,000 square feet, or nearly 3.5 acres, which will cover all but the most extensive ponds with room to spare. Order them in any size you need, and they can be custom cut and fabricated to match the size of your pond, including box inserts for a formal pond with vertical walls. BTL’s experienced staff are happy to jump on the phone with you to help you choose not only the best liner product but the best shape and size for your layout. BTL also offers videos for quick reference along the way, including this example showing how to measure your pond for a liner.

Liners by BTL

AquaArmor Pond Liner

The most versatile liner on the market today, AquaArmor maximizes protection from harmful UV rays, tear resistance and punctures that cause leaks. Simply the best liner on the market.

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