Key Features of Quality, Long-lasting Pond Liners
The #1 choice hands down is "fish safe" 45 mil EPDM rubber. Though there are a few excellent options for pond liners available to the water garden or Koi hobbyist, EPDM (Ethylene-Propylene-Diene-Monomer) is at the top of the list.
Do not settle for anything with less thickness than this.
I cannot stress this enough. Also make sure it is labeled "fish safe". I have no connection to Firestone, however one way you can be sure your liner is fish safe is if it carries the Firestone PondGard logo.
I personally have Firestone brand 45 EPDM liner in my Koi pond, which was installed in 2000 and it is holding up just like it is supposed to. It also carries a 20 year warranty.
Another important feature is EPDM is extremely flexible. This comes in handy when working with the irregular twists, turns, and shelves commonly found in a garden pond or stream installation.
EPDM easily drapes into the excavated area and conforms to all of the nooks and crannies in the application. EPDM is very stretchable and extremely resistant to punctures. It is also very flexible even in extremely cold temperatures.
Thinner rubber is more prone to rips or punctures during installation, and possible punctures on-up-the-road once installed.
Roofing Rubber is Not Fish Safe!
I do know of a few people who have bragged about saving a lot of money by buying the rubber used under roofing shingles. Please don't use this stuff ... to do so is a big mistake. Roofing rubber contains heavy metals and will kill your fish and stunt your plants.
Fish safe liners are given a stamp of approval by the manufacturer. This means they guarantee that the membrane is chemically compounded to be fish safe, and that it's officially verified by testing to ensure that it is not toxic to fish.
Pond Liner Warranties
Don't even consider using a pond liner if it doesn't come with a long term warranty. Higher quality pond liners will usually come with a 20 year warranty. The warranties imply that the liner will not prematurely deteriorate because of weathering within the 20 year period.
THE SUN'S ULTRAVIOLET RAYS
ARE THE PRIMARY CULPRIT
IN THE DETERIORATION OF MOST LINERS
Size Limitations to EPDM Pond Liners
The only limitation to EPDM pond liners is the largest roll size manufactured is 50ft x 100ft. For most of us backyard ponders, we will never need a piece this large. However that being said, here are a few seaming facts, so that you are informed. EPDM can be difficult to seam effectively because:
- Weather conditions have to be perfect in order to properly complete a seam.
- Moisture, such as rain or cold, damp conditions can affect seam quality.
- You need to have a good, flat foundation in order to perform the seaming process: driveways, yes ... lawns, no.
- The edges where you will be seaming must be prepared by cleaning with unleaded gasoline.
- Seam tape can be very frustrating to work with. It wants to stick to everything, including you!
- Seam glue or "lap sealant" is also not always easy to work with.
- A hair dryer (extra heat) needs to be used in some of the steps for maximum adhesion of the new seams.
Now, this is not to say that many people and professional pond installation companies don't have to sometimes seam together EPDM. Often this procedure is done in the situation where a stream bed section meets up with the pond liner section. I'm just letting you know it is not a fun nor easy task, but it is doable.
Other Types of Acceptable Pond Liners
I won't go into a long discussion on the various reinforced polyethylene pond liners. These usually tend to be used in garden pond installations that require something bigger than a 50ft x 100ft piece. However, people do use this type for smaller installations. Some of the pros and cons are:
- Flexibility, durability and fish safe features are inherent in this type
- Custom sizes can be made by the factory
- This type is much easier to seam, however a professional level of expertise is required
- This type is not quite as flexible as EPDM
- This type can cost a few more cents per square foot than EPDM
- It may not hold up as well to "abuse" during installation of large stone placement around the pond.
In closing, there are many types of pond liners to choose from. Advertisements claiming "lighter weight" or "more tear resistant" are frequently seen in water garden publications. But in most everyone's estimation, professionals included, the material of choice is 45 mil EPDM. Especially for those of us who are do-it-yourselfer's, nothing else really compares to the quality, flexibility, strength, durability, and cost-effectiveness of EPDM.
Continue to Pond Liner Underlayments >>
