How Much Do Pond Liners Cost?

Average Pond Liner Installation Cost*

*For a 12-by-12-foot pond

Pond Liner Costs by Material

The average costs of general line products like vinyl and rubber range from as little as $0.35 per square foot to as much as $120 per square foot. Note that the low prices for rubber and plastic come from the ability of homeowners to buy large liners over 10,000 square feet. Smaller products tend to be more expensive per square foot because they don't have discount rates.

A pond liner is the material used to mark where a pond should be and protect dirt and other debris from slipping into the water. The liner additionally prevents erosion. A professional can help choose the right material for any property to prevent breakage, seepage, and other forms of damage.

Flexible Rubber, Butyl, or Polypropylene

Flexible rubber costs about $0.50 per square foot on average, making it one of the cheapest options. It is easy to install and works well in small ponds. It tears easily and might degrade from sunlight.

Rigid Plastic

Rigid plastic is used on only small liners and is inexpensive at $0.75 per square foot. People usually find plastic in premade garden or koi ponds. It might degrade from the weather and sunlight.

Bentonite Clay

Bentonite clay costs $1.15 per square foot and forms an active liner that can be reapplied easily. It is also called blue clay. The clay interacts with water to form a tight seal. It's difficult to install correctly the first time for novices and often needs replacement because of DIY errors.

HDPE

High Density Polyethylene is a form of rubber used in the liners of large projects like farm ponds. It lasts for a long time for only $0.62 per square foot.

Firestone

Firestone sells EPDM liners in a variety of sizes. The average price is between $0.25 and $1.30 per square foot.

EPDM

EPDM serves as weather-resistant rubber, safe to have around fish and aquatic plants like the ones found in koi and fishing ponds. It is inexpensive at $0.85 per square foot.

PVC

PVC forms a synthetic vinyl that stays flexible at most natural temperatures and is safe for aquatic life, making it popular in fishing and natural swimming bodies of water. It only costs $0.65 per square foot.

Spray-in

A spray-in seal is a liquid synthetic coating, usually rubber, applied as a spray and then allowed to dry. These sprays are more flexible than other options but also more expensive at $2.60 per square foot.

Polyurea

Polyurea forms a liquid coating applied hot and then allowed to dry to form a watertight seal. It is $1.50 per square foot and does not degrade from erosion or sunlight, so once applied, it will be around for a long time.

Akwaseal

Akwaseal is the combination of bentonite clay and a plastic membrane for smaller ponds. It costs $1.90 per square foot.

RPE

RPE is a flexible synthetic pond liner that is fish and plant safe. It is $0.84 per square foot and typically used in larger gardens, fishing, or farm ponds that will have a lot of aquatic life.

Pond Liner Cost Calculator

Hardware and garden stores carry liners. Many swimming pool retailers also sell them in smaller sizes that work well for ponds. The easiest way to measure is by figuring out the length, width, and depth of the body of water in terms of square feet, yards, or acres. Property owners should also know how many gallons of water are needed to fill the pond and should again know the length, width, and depth.

Homeowners can figure out the size of their liner using this formula with all measurement units: (Length + (2 x Depth + 1)) by (Width + (2 x Depth + 1)). Check out the guide below to measure for your pond liner.

Per Square Foot

Most ponds measure by square footage and have standard lengths, widths, and depths.

Per Yard

Retailers do not sell liners by yard because it is a difficult unit of measurement to work with. However, there are 9 square foot in 1 sq. yard, which comes to an average price of $18 per square yard.

Large Pond or Lake Costs per Acre

Liners for large lakes tend to be expensive because there are so many square feet in a single acre. The chart below shows the average cost at a discounted rate of $0.25 per square foot.

30 Mil. vs. 45 Mil. Rolls

EPDM and many other synthetic rolls have thicknesses measured by thousandths of an inch so homeowners can understand their strength and flexibility. 30 mil rolls are the most popular type and is the standard thickness. They resist tears and have enough to survive regular exposure to the elements. Thicker rolls are usually 45 mil while thin, inexpensive models might be 15 mil. The smaller the number, the weaker the material.

By Gallon

There are 7.5 gallons of water in one cubic foot, calculated by multiplying the pond's length, width, and depth. So, for a body of water that is 100 cubic feet, needs 750 gallons of water. Purchasing a pond liner by this measurement is difficult since gallons need to be turned into cubic feet and then square feet for accuracy. To do this, divide the total number of cubic feet by the depth of the body of water. The result is how many square feet the pond is.

• Ex: Cubic Feet/Depth = Square Feet

• Ex: X gallons = y cubic feet

Cost to Add or Install a Pond Liner

People wishing to install a pond liner need to figure out the cost for the materials as well as labor. Most landscapers or installers charge $25 to $30 an hour. The average price for a 12x12 pond falls around $1,000. This amount depends on factors related to installation as well as materials.

Soil Type & Land Conditions

The soil type and land conditions around the pond can affect the type of liner needed. A few methods exist to figure out what homeowners have in their yard. A simple soil test costs $10-$20 at the home improvement store but a more useful professional variety that decides quality and density sets someone back $400. Landscapers charge $45 to $75 an hour, but also have the experience to tell if the soil will slide into the pond site or is too dense for work.

The liner helps prevent seepage or the soil from leaking into the water and ruining the shape and environment of the structure. Some solid materials, such as fiberglass, last a long time and hold their shape for decades.

• Clay: can be one of the worst soil types to have because it is difficult to dig and doesn't hold water.

• Grass or Soft Ground: Simple surrounding land conditions like grass or soft ground are the easiest to line because they don't move much or have materials that can puncture. Homeowners with this kind of property can get away with cheaper, inexpensive liners.

• Difficult Conditions: Homeowners with difficult land conditions need to spend more to buy a thicker liner. Tree roots and rocks easily puncture thinner materials like vinyl, which is why it's important to invest in a thick rubber. Contacting a professional helps property owners avoid problems in the long run.

Fish Safe Liners

Interested individuals find fish safe pond liners which don't leak any harmful chemicals or deteriorate from UV radiation at pet and landscape stores. Most liners are made of synthetic materials like rubber and are easy to cut and shape. They cost between $500 and $8,000 depending on the total square footage of the pond.

Natural Swimming Ponds

Natural swimming ponds use the same liners as swimming pools because both prevent seepage and are safe for humans. It costs almost $2,000 to have one installed on average. The average cost to install a swimming pond liner is between $900 and $3,000.

Cost to Replace a Liner

Removing fish or aquatic plants first when replacing a liner add extra expenses. Workers pull away the old material to lay down a new one. People who DIY this task need to pay for a new one, which will cost the same as the old unless they pick a different material. Professionals tend to charge between $1,000 and $2,000 to replace everything. This price excludes the expense of the liner itself.

DIY Pond Liner Installation vs. Hiring a Pro

For smaller landscapes and ponds, you may find installing the liner yourself saves you some money to put towards other materials like new plant life or pond features. 

Only tackle this project if you feel confident in your ability to install it correctly; poorly installed liners can result in dramatic drops in your water level (think over the course of a few days). If you have a large pond, it’s best to leave that to a local pond installer.

Installing the actual liner is relatively easy, but prepping the space beforehand is critical to ensure your liner doesn’t leak or tear. This includes:

1. Making any sharp angles (like from concrete or stone around the pond) dull by softly knocking it with a mallet.

2. Ensuring the slope to your drain is properly installed to avoid water pooling.

3. Removing any covers for drains, lighting, or other in-pond fixtures, which will go back over your liner once installed.

4. Installing a protective underlayment for the pond liner to go over. This prevents any holes or tears that may cause leaks in your liner.

Once you complete the above steps:

1. Roll it out next to the pond and start to lay it over your pond. Depending on the size, you may need 2–5 additional people to help carry it evenly over.

2. In 2–5 feet increments, start smoothing out your liner to the best of your ability to ensure there isn’t too much bunching in certain areas. No need to be perfect, as once you add water the liner will flatten. You also don’t need your liner to be tight, as that can cause tearing.

3. Cut any holes in your liner to account for drains, lighting, or other fixtures, and reinstall the covers on top of the liner, adding screws to secure.

4. Secure your pond liner by using rocks or landscaping material (if a smaller pond) or in an anchor trench (if a larger pond).