Pond liner with rocks on it

Are you in the market for a pond liner that will make your home oasis look and feel like a dream come true? Are you wondering how you can pick the best one with so many types of liners available and different factors to consider?

If so, you’ve come to the right place! In this blog post, we’ll cover everything you need to know about pond liners, from the different types and materials available to our favorite products on the market and useful installation tips.

So keep reading to learn all about the different types of pond liners, and by the end of this article, you’ll know exactly what pond liner will work best for you.

Our Favorite Pond Liners

It can be tricky to choose the right liner for your pond, but don’t worry! We’re here to help. Let’s start by going over the different types of pond liners.

Types Of Pond Liners

Preformed Pond Liners vs Flexible Pond Liners

When it comes to pond liners, there are two main types to choose from–preformed and flexible. Each one has its own advantages and drawbacks, so it is important for pond owners to decide which type is going to be best for them.

Preformed pond liners: These are rigid and are available in limited shapes. They are typically made from molded plastic or fiberglass.

Flexible pond liners: As the name suggests, these liners can be custom-shaped to fit any pond shape. They are made out of various types of plastic with specific qualities (more on that later). Pond contractors typically use flexible pond liners since they allow for more customization options.


Most preformed pond liners are made out of fiberglass.


  • Fiberglass pond liners are durable and strong
  • UV (ultraviolet) resistant
  • Resists cracking
  • Withstands extreme temperatures well
  • Easy to install–simply insert the liner into an appropriately sized hole


  • Since they are preformed, you are limited to whatever shapes and sizes the manufacturer offers
  • Expensive to ship due to their bulky size
  • May emerge from the ground in heavy rain if water gets between the liner and surrounding soil


PVC pond liner is a synthetic material made of polyvinyl chloride.


  • Good resistance to punctures
  • Relatively lightweight
  • One of the least expensive pond liner materials
  • Can be easily expanded by attaching two sheets together with liner tape


  • Low UV resistance
  • Can crack in extreme cold
  • PVC pond liners can leach harmful chemicals into your pond water and surrounding soil (so not good for koi ponds)
  • Somewhat difficult to install because of its tendency to wrinkle or crease


EPDM (ethylene propylene diene monomer) is a synthetic rubber pond liner.


  • High UV resistance
  • Very flexible, so it works well in irregularly shaped ponds
  • Won’t crack in extreme cold
  • Does not leach chemicals
  • Easily expandable with liner tape


  • Can be prone to punctures, so it should be paired with underlay
  • EDPM is quite heavy, so DIYers might find it harder to work with than with other types of flexible pond liners


High-density polyethylene (HDPE) and reinforced polyethylene (RPE) are synthetic rubber pond liners.


  • Good UV resistance
  • Fairly lightweight material
  • Very flexible and puncture-resistant


  • More expensive
  • Can’t be expanded with liner tape, must use a heat gun
  • Difficult to repair if punctured

Considerations For Picking The Right Pond Liner

Pond liner laid in a stream

When it comes to pond liners, one size does not fit all. Different pond liner products offer a variety of features and price points and are appropriate for different types of pond applications. So how can you pick the right liner for your project?

When it comes to picking the perfect liner for your backyard oasis, there are several aspects you should consider. Here’s an overview of 5 of the most important ones.


It is important to consider not just their practical purposes but also the aesthetic value they can bring. For example, if you use a preformed liner, the edge will be partially visible above the ground. If you are aiming for a more natural look, you’ll either want to obscure the liner edge with plants, rocks, or other types of landscaping or choose another type. Flexible pond liners, no matter what color they are, can be covered with rocks and gravel for a more natural look.


Liners that are prone to punctures should always be installed with an underlay for protection. However, even puncture-resistant ones will benefit from an underlay if your soil has a lot of sharp rocks or roots present. Some manufacturers will include an underlay, while others require you to purchase an underlay separately.

UV Resistance

Over time, all liners will degrade in sunlight. However, some liner materials have higher UV resistance than others. Too much exposure to direct sunlight can quickly degrade liners without proper UV protection, leading to dry rot and pond liner failure. Besides investing in a pond liner with good UV resistance, adding floating plants or shade structures is another great way to provide some relief from sunlight over your liner.


A thicker liner will be less prone to puncturing, tearing, or cracking. Although thicker pond liners are more durable and generally last longer, they also tend to be more expensive. Liner thickness can also affect shipping costs (if you are getting it delivered) and ease of installation (thicker pond liners are harder to install).


Last but not least, you’ll want to consider what material the liner is made out of. Some pond liners have higher UV resistance, greater flexibility, and are more puncture-proof simply due to the material they are made out of. Other liner materials may not be ideal due to their tendency to leach chemicals into the environment.

Our Favorite Pond Liners

Laid in pond liner

Here at Gradex, we prefer to use EPDM pond liners due to their strength, flexibility, UV resistance, non-toxicity, and overall superior performance. However, in order to provide the best product overview for pond owners who may have different liner requirements, we have highlighted our favorite pond liners from each of the 4 types we discussed in this post.

1. LifeGuard Pond Liner 30 ft. x 35 ft. 45 Mil EPDM Rubber and Underlayment Combo

This 45-mil thick EPDM pond liner is the perfect liner for average size ponds. This durable and UV-resistant pond liner also includes an underlay.

2. Pondliner.com PVC Fish Pond Liner 30’ x 36’

This 30-mil thick PVC pond liner contains UV stabilizers that help protect it from degrading in sunlight. Besides standard black, it is also available in a light blue color for a more natural look.

3. Vevor 16.4 ft. x 19.7 ft. 20 Mil Thickness Waterproof Aging-Proof HDPE Pond Liner

This 20-mil thick HDPE pond liner can last for up to 10 years under intense sunlight, according to the manufacturer.

4. Algreen 91901 Avonlea Rigid Preformed Pond Liner, 33-Gallon ,Black

This 33-gallon preformed pond liner is the perfect starter pond for someone with limited space. It is safe for fish and plants and includes easy-to-follow installation instructions.

Pond Liner Installation Tips

Installing pond liners is no small task, but with a few basic tips, you can have a pond that looks professionally done. Here are some useful installation tips for making sure your liner installation goes off without a hitch.

  • Measure the pond size twice and buy a liner at least several feet longer on each side to accommodate for ridges and valleys on the pond bottom
  • Add a layer of sand or other insulating material (such as old newspapers) to help protect the liner from sharp rocks or roots
  • Use an underlay for even more protection
  • Use rocks to hold the liner in place while you fill it. You can also use rocks and plants to hide the excess liner after the pond has been filled


Installing one of the types of pond liners

What is the best pond liner?

Here at Gradex, we prefer EPDM pond liners for their long-lasting durability.

What is the ideal thickness for a pond liner?

The ideal thickness for a liner depends on many factors, including the material and the environment you are installing it. That being said, we recommend not going below 20 mils.

Is a pond liner necessary?

All manmade ponds should have a liner unless you are creating a pond out of concrete or another impermeable material.

Is UV protection necessary?

Absolutely! If your location gets lots of direct sunlight throughout the year, then UV resistance is a must-have quality for your liner. Without it, certain materials may degrade quickly due to exposure to sunlight.

Let The Experts At Gradex Build Your Perfect Koi Pond

When selecting a pond liner, there are many factors to consider, such as aesthetics, underlay needs, thickness requirements, and UV resistance levels. We hope this pond liner blog post has given you the knowledge to determine the best liner for your backyard oasis.

If you have questions about pond liners or want help building your own backyard pond, our team at Gradex is here to help. Just fill out our contact form, and we will get back to you ASAP.