Your liner selection is critical at this point in your project. Some liners cannot ship in large panels due to their weight or stiffness and require joining multiple sheets together. This step creates a weak link and represents the most common source of leaks, whether you're taping, gluing, or heat welding. PVC panels must be glued together in a slow, tedious process to ensure a perfect seal. EPDM uses both a spray adhesive and double-sided tape, which also involves a tedious, time-consuming process. RPE can be heat-welded in the field, which is considerably faster. Fortunately, this is rarely needed in all but the largest ponds since it's available in such large panels and can be custom fabricated by BTL in the factory. Simply put, all other things being equal, a seam-free pond liner is more secure and presents a lower risk of expensive repairs.
During installation, the differences in materials come into sharp focus. Heavier geomembranes like EPDM may require lifting equipment to move the liner into position for deployment. Thick or inflexible materials like HDPE can be awkward to conform to tight corners, making it hard to keep in place and detracting from the overall appearance of the pond.
Maintenance
Superficially, maintenance is similar for any type of pond liner: regular removal of leaves, branches, and other debris, vacuuming out accumulated muck and trimming overgrown plants apply no matter the type of pond you have. The key difference comes in the relative ease of performing these chores. Less durable pond liners that are vulnerable to punctures (EPDM and HDPE) or tears (PVC and LDPE) need a much gentler hand, whether you're poking the pond vacuum into hidden nooks and crannies or pulling out branches that fell in last week's storm. A broken branch with sharp edges can rip a sizable hole in your liner if you do so much as lose your balance for a moment. It makes sense to avoid stepping into your pond whenever possible, but a durable, reinforced liner is much more suited for such unexpected mishaps.
Prioritizing Your Budget
In the end, the type of liner is one of the most important decisions you'll make when installing a new pond, and yet, many people think they can skimp on this element. You'll see discussions about reusing old tarps, roofing membranes, or even plastic drop cloths. A cheap liner that's prone to tears or punctures, that's too thick and unwieldy to conform to the shape of your pond, or that exposes your fish and plants to toxic chemicals will cost more in the long term than you saved at the outset. Considering the expense, time, and stress to both your fish and your family life that a rebuild will involve, is it worthwhile to select a low-quality liner for the sake of a tight budget? If you're facing this kind of situation, take a careful look and evaluate whether you can delay some other elements (statuary, decorative stones, nearby plantings, a few expensive fish) in favor of a dependable infrastructure (including liner, pumps, and filters) for your pond.
