The material best suited as a liner for a heavy duty pond project is not obvious unless the entire project is taken into account. Western Environmental Liner supplies Geomembranes that exceed industry standards for tear and puncture resistance and warrants these for as much as 20 years of service life, but we always recommend a consultation before writing specifications – because the choice is not obvious without considering numerous factors.
Standard engineering thinking on heavy duty pond liners tends to rely on a strict PSI metric as well as focusing on the measures of thickness and weight. But these metrics are not the ultimate indicator of what’s best for the project: we really want to know about puncture and tear resistance under field conditions and PSI, weight and thickness specifications alone don’t give us that. In our experience, the tightness of the weave is more important than the overall tensile strength or pressure resistance of the composite material, because a liner still has to conform to the surface of the pond bed, as well as needing maximum flexibility during transportation and field installation.
We have a thorough examination of the elements to consider and the metrics to use when choosing the correct pond liner in this article: Why Weight and Thickness are Not the Final Specs for Geomembrane Liners.
A heavy duty requirement for a pond liner usually indicates higher stresses involved, something our Aqua 30 Coextruded Polyethylene Liner is good for. This is one of our newer formulations, with the tear strength and puncture resistance of our reinforced polyethylene (RPE) liners, and with an extra coextruded layer of coating.
Our 30 mil Coex is a great illustration of how a strict comparison of weight and thickness alone is not the best spec for a heavy-duty pond liner material. This material is stronger than a 60 mil HDPE (high density polyethylene) and it performs better, but it weighs about half as much and is about half the thickness. These qualities mean that in the field – which is where every project specification meets its real test – the material can be shipped folded and in larger panel sizes, in turn requiring less welding on site, more conformity to ground surface, and easier handling during installation. All these factors act to minimize puncturing and tearing and materials fatigue.
In general we find that RPE is better than HDPE for large, heavy duty or mission-critical pond liners – see our article for a better examination of the advantages: Why RPE is Often Better than HDPE for Pond Liners. And although we have pioneered the tightest weave in the industry with our liner materials, we understand the role played by coatings, as the 30 mil Coex shows.
We create products that work to match the field conditions and ultimate requirements for pond liners, for the greatest performance benefits in weight, flexibility, cost, tear strength, puncture resistance, UV resistance and durability. All these factors come into the cost-performance estimate before beginning the project. See our article for a broad review of these elements: Costs to Consider with Every Pond Liner Project.
And finally, one of the most overlooked aspects of any pond liner is its ease and cost of installation. In our experience of more than three decades, much of the damage to a liner that results in ultimate leakage and failure is caused during installation. We use our own crews, but many projects rely on contractor crews. Seam welding in the field is probably the most critical part of an installation, and this should be done correctly, and verified. See our article detailing the most important things to consider in installation: Installation Tips and Pitfalls with Pond Liners.
In summary, for a heavy duty pond liner specification, it’s crucial to weigh all the elements of the project to come up with the optimum geomembrane to use. Shipping and installation costs are a large factor not always obvious or accounted for in a purely engineering specification. Size of fabricated panels, number of field welds required and material fatigue from shipping and handling all come from choice of material, and can be the making or breaking of any project. Always take advantage of our free consultation before writing pond liner specifications, for the success of your project.
Heavy Duty Pond Liners
December 11, 2020