Once installed, how long will your pond last? That’s an important question. Finding the answer will determine how much your pond liner really costs in the long run. When you consider what must be done to drain a pond, tear out existing materials, and do a whole new installation, you’re looking at substantial costs. The more times this must be done over a given time period, the more your costs are increased. When doing an apples to apples comparison, not only do you need to consider the cost of materials and installation, but you also need to calculate the cost of replacement and the potential new build of a pond multiple times verses using long lasting, flexible liners.
The Lifespan of a Preformed Pond
An inexpensive preformed pond liner, purchased at a local hardware store, doesn’t come with a warranty. Unfortunately, that same pond liner is likely to be cracked and/or leaking within five to ten years after installation. Even preformed pond liners that are warrantied are only covered, at most, ten years and with good reason. The average lifespan of a preformed pond liner is ten years. And although a few will last as long as 15 years, many will never make it to the ten-year mark. This means that in addition to designing and installing a whole new pond with a new liner, you’ll also need to tear out the original pond.
The Lifespan of Flexible Liners
Flexible liners, on the other hand, are often guaranteed to last for 20 or more years. Some reinforced flexible liners, such as BTL Liner’s RPE flexible liner AquaArmor, can last for decades with a covered installation and proper maintenance.
Worried about the seams? If installed correctly, the seams will last as long as the liner itself. Heat-welded seams tend to last longer than those using sealants; therefore, for greatest durability, choose a liner that is heat-weld compatible. Common flexible liners that can be heat-welded include LDPE, HDPE, RPE, Polyethylene, and PVC. EPDM and Butyl cannot be heat welded.
Prolonging a Liner’s Lifespan
It’s important to note that many circumstances affect the lifespan of a flexible liner. The type and thickness of the material, as well as the conditions the liner is exposed to, will all impact its longevity. When exposed to direct sunlight and other degrading elements, even the highest-quality flexible liner will have a shortened lifespan.
The longevity of both flexible liners and preformed pond liners is increased when the liner is protected from direct sunlight. This includes more than covering the exposed edges of the pond liner. The parts of the liner that are underwater also need to be covered by spreading sand and rocks over the bottom and sides of the pond as well. When covered with a thick enough layer of material, the liners are protected from the degrading effects of ultraviolet rays. Liners that are exposed to ultraviolet rays break down faster and become brittle, unless they are specifically formulated to withstand exposure. Due to the design of preformed ponds, which includes vertical surfaces, protecting the walls becomes exceedingly difficult, causing a material that is already somewhat brittle to become even more so.
Alternatively, some flexible liners are designed to be UV resistant. BTL Liners fabriates a multi-layer RPE liner, AquaArmor, which is highly resistant to ultraviolet rays, giving it a decades long lifespan, even when exposed to these conditions.
Conclusion
With the lifespans of flexible liners being, at a minimum, twice as long as that of preformed pond liners, flexible liners are the clear choice when it comes to longevity. The cost of multiple installations for the preformed ponds and the cost to tear out the existing pond to install the new ones easily exceeds the original upfront cost of flexible liners which are generally more than that of the preformed pond.
As you compare preformed ponds to flexible liners, it's important to lay out your budget considering liner replacement costs. If you look at only the initial costs of materials and installation without considering longevity and replacement needs, you may spend substantially more in the long run when additional installs and removals become necessary. When it comes to lining a pond, it pays to think long-term.
