3 Things You Didn't Know
About Pond Liners
Pond liners are used in ponds to keep water from seeping into the soil. They work by forming an impermeable layer between the water and the soil which prevents water loss.
Pond liners also provide a base for plants to root themselves in and provide a comfortable environment for fish to explore. Various methods, including layers of sand and geotextiles, are used below the liner to protect liners from sharp objects.

1. Liner Materials
There are several different types of pond liner materials. The most common materials are EPDM, RPE, and PVC liners. Here are various liner material options:
RPE- Reinforced Polyethylene Pond Liners
Reinforced Polyethylene liners (RPE) are one of the most durable pond liners available. They can last up to 40 years and have excellent puncture resistance. RPE liners do not need a protective underlayment because of their higher strength. RPE can also be produced in large sizes because they are lightweight. RPE liners do not bend as easily as other flexible liners, which is one drawback of this type of liner.
Box Welded Polypropylene Liners
If you are considering options for regular or circular pond liners, you should consider box-welded polypropylene. Box welded polypropylene liners are durable and light. They are also UV resistant and safe for fish and plants. Box-welding is a process that uses heat to weld liners to conform to various 3D shapes. Box welded polypropylene liners allow you to have corners that are seamless and without folds.
Rubber Liners
Rubber liners are heavy compared to other liner materials and they are not as puncture-resistant. Despite this, rubber liners are flexible and can fit nicely in ponds that have shelves and a variety of other features. With rubber liners, you can’t heat weld multiple panels together. You can, however, join sheets together with liner tape. Punctures or tears, leaks in seams, and age and deterioration are all factors that risk the chance that small rocks, tree roots, or other objects may remain in the hole excavated for the pond.
The weight of the water pressing down on the liner may be heavy enough to puncture it. To decrease the chances of your liner tearing, you should get a strong liner material. Pond liners are typically made out of multiple sheets of liner material that are welded together. Leaks can occur anywhere where a seam joins two sheets. The best option to avoid seam leakage is factory-welded custom pond liners. Factory-welded pond liners work by using advanced technology to produce consistent welds.
The welding takes place under conditions that are not subjected to a variety of factors. Welds made in the field during installation, however, are often subjected to the weather, uneven grounds, less sophisticated equipment, and other factors that can compromise the welds. One other factor that you may consider when choosing a liner material is whether or not your pond will have a dock. If your pond has a dock, the columns on the dock will penetrate your liner. This will create a point where leaks can occur. You should go with a custom liner with column boots for the dock to avoid this problem.
2. How Liners Develop Leaks
Punctures or tears, leaks in seams, and age and deterioration are all factors that risk the chance that small rocks, tree roots, or other objects may remain in the hole excavated for the pond. The weight of the water pressing down on the liner may be heavy enough to puncture it. To decrease the chances of your liner tearing, you should get a strong liner material. Pond liners are typically made out of multiple sheets of liner material that are welded together. Leaks can occur anywhere where a seam joins two sheets. The best option to avoid seam leakage is factory-welded custom pond liners. Factory-welded pond liners work by using advanced technology to produce consistent welds.
The welding takes place under conditions that are not subjected to a variety of factors. Welds made in the field during installation, however, are often subjected to the weather, uneven grounds, less sophisticated equipment, and other factors that can compromise the welds.
One other factor that you may consider when choosing a liner material is whether or not your pond will have a dock. If your pond has a dock, the columns on the dock will penetrate your liner. This will create a point where leaks can occur. You should go with a custom liner with column boots for the dock to avoid this problem. In order to avoid leaks, your pond liner also needs to age well. The liner material must be resistant to UV rays and to weather. Pond liners are made out of synthetic materials that consist of long-chain molecules.
UV rays can break these molecules over time which can cause liner materials to become hard and crack. You can avoid this by choosing a liner material that is UV resistant or has a protective coating.

3. Choosing the Right Liner Material
Choosing the right pond liner depends on your specific needs and environment. For a pond liner, the most important characteristics are flexibility (to better fit the dimensions of your pond), strength and resistance to stretching, puncture resistance, weight (for easy handling), UV resistance, non-toxic, and long lifespan.
However, before you choose the right liner material, there are certain factors you should consider when determining if you should get a liner material for your pond:
- Existing water – Even though many ponds retain some water, it is not recommended to line a pond that contains more than a quarter of its fill capacity for an extended period of time. If your pond is more than a quarter full and you’re looking for the right liner, you would need to drain the pond before laying the liner or put at least two inches of soil on top of the liner.
- Pond size – To see if a liner material is the best option for you, you should use a tape measure to measure your pond. Determine whether your pond may be too small or too large to use a liner material.
- Slope – Steep slopes can cause premature wear by putting too much stress on a liner. PVC and RPE liners are designed to be used in ponds that are no steeper than a 3:1. Determine what the slope of your pond is to decide whether or not a liner material works for you.
Ponds provide an excellent recreational location in your own backyard. If you are a landowner who is not able to hold water with just soil, liner materials are an excellent way to retain water.
Reef Industries Inc. manufactures Permalon®, a uniquely engineered alloyed high-density polyethylene cross-laminate. This patented product offers excellent physical properties, outstanding service life and is non-toxic to fish. High strength and high-performance Permalon® materials are available in stock configurations for immediate availability or can be custom fabricated to your specific requirements including drop-in configurations. Designed to be lightweight and easily handled, Permalon® pond liners are reliable and cost-effective.