What is the Best Pond Liner Thickness for Your Pond?

April 25, 2024
what is the best pond liner thickness

What pond liner thickness do you need for your pond?  That answer depends on two things:

1. The liner material you use, whether it’s HDPE or RPE

2. What you plan to store in your pond (water vs. waste/chemicals)

Liner Material is Key

Your pond liner material is a critical factor in determining the thickness you need, and its role is often misunderstood.  Quite often we need to convince people that – if they choose the right material – the liner doesn’t need to be as thick as they think.   

We’ve been making pond liners for 30 years.  In our experience, many engineers who call us still want thicker, heavier liners based on a spec they pulled from an old engineering handbook.  That old handbook ignores the huge advances the industry has made in recent years. 

Today the pond liner industry is moving toward materials that are stronger, lighter and thinner.

Choosing the right material means you can achieve your leak tolerance requirements and at the same time have a liner that’s easier to transport, easier to install and whose overall cost is less.

RPE Pond Liners

The key here is choosing an RPE (Reinforced Polyethylene) liner. These liners are the best overall choice for most pond applications.   RPE is a strong film made by laminating two layers of polyethylene with a heavy-duty scrim reinforcement in between. The scrim is made of HDPE thread that makes the liner stronger.  RPE is also coated on both sides to increase its durability and resistance qualities.

RPE liners are 2-3 times more puncture-resistant than a traditional HDPE liner.  That strength allows you to use a thinner liner for your job. 

HDPE Pond Liners

HDPE (High-Density Polyethylene) liners are an older type of geomembrane material. HPDE is thick and strong and has advantages over both PVC and EPDM.  It has a long life and sheets of HDPE can be welded together to make custom liners for larger ponds. 

HDPE contains a loose weave to hold the liner together but is primarily chosen for its denseness. As a dense material it’s also somewhat stiff, even rigid.  

That stiffness can be a challenge when you transport an HDPE liner to the job site. You can’t fold HDPE, so you need to roll it, which increases your shipping costs.  The stiffness of the material also makes it harder to install, which raises your installation costs.  

As a rule, choosing HDPE means that your liner will need to be thicker than an RPE liner and it will be harder to handle.

How Liner Material Affects Thickness

In practice, a 30 mil RPE liner is preferable to a 60 mil HDPE liner for most applications. The superior strength of RPE means you just don’t need the same liner thickness.  

And, while a square foot of RPE costs more than a square foot of HDPE, a 30 mil RPE liner will still be cheaper than a 60 mil HDPE liner.  That’s especially true when you factor in the higher shipping and installation cost of the 60 mil HDPE liner.  

Key takeaway:  Choosing an RPE liner means you can use a thinner liner that’s easier to ship and much easier to install, saving you money.

Pond Liner Thickness Based on What’s Being Stored

As a rule, you can use a 30 mil RPE liner for ponds that store water.  That means that farm ponds, irrigation ponds, stormwater retention ponds and similar applications can use a 30 mil liner. 

Use 40 mil RPE for waste applications. That means if your pond is storing chemicals or biological waste, opt for a thicker RPE liner.  

If you have a particularly high requirement for puncture resistance, consider using a double scrim RPE liner.  These liners are even tougher –  you can literally drive a truck over them without damaging the liner.

Use a 60 mil HDPE liner for applications that are especially challenging, such as demanding oil & gas ponds.  

Call Us For Guidance

If you’re still not sure what liner thickness or material is right for your job, call us at 1.844.202.4241. We’re happy to give you our guidance. 

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