With careful construction and the right liner, it’s possible to build a pond that doesn’t develop leaks for decades. However, choosing a preformed pond liner makes this much harder. When a leak develops in a preformed liner due to damage or age, it’s tricky to deal with the problem. Leaks are never easy to find or patch, but it becomes downright impossible with the wrong kind of liner. Having to tear out the entire pond liner and replace it because there’s a leak is a wasteful, difficult, expensive repair.
Cracks and Pinholes
First, the types of leaks that form in preformed pond liners are hard to spot when the pond is filled. The rigid material is prone to cracking so that it looks intact but is slowly losing water. Since most preformed pond liners are small, these ponds can drain overnight before you notice a problem. Pinholes also commonly form in the weakest parts of preformed liners without any noticeable visual change. If you can’t find the leak in the preformed liner, there’s no way to fix it. Many people buy multiple preformed liners and experience the same kinds of leaks with them until finally switching over to a flexible material that is more damage resistant.
Testing the Liner
There’s no way to reliably test a rigid liner to see if it’s leaking or to find compromised areas. You can set the rigid liner up above ground and look for leaks, but this can damage the shell since it’s not being supported by the soil. If the liner’s in the ground, there’s no testing equipment to register the leak. When you know your rigid liner is leaking, the main technique for dealing with the damage is to replace the entire liner rather than finding the problem and patching it.
Causes of Damage
Rigid liners are easily damaged by solid ice in cold climates where the entire body of water freezes solid. The ice expands in all directions, putting a lot of pressure on even the toughest plastic and fiberglass liners. Despite being reinforced with fibers, fiberglass liners tend to crack more easily than plastic ones. Surface freezing still adds extra wear and tear to the pond liner, increasing the chances of a stress crack that forms in a molded shelf or lip area. Tree roots also commonly damage rigid liners as they press up against the material. Flexible liners are less likely to experience root damage because they bend with the pressure instead of cracking.
Falling stones that break loose of the surrounding decorative features also cause a lot of damage to rigid liners. Since natural stone is usually used around ponds for an authentic look, a single slab mounted on the edge or a waterfall can weigh hundreds of pounds. Rocks often work their way loose from the mortar over time as water erodes the bond between the two materials. Flexible liners are rarely torn from a loose decorative rock since they can bend and stretch with the force instead. Finally, foot traffic around the pond from humans or animals can crack the material and fracture the edges. These cracks cause leaks if they spread below the surface of the water.
Patching Options
It’s very difficult to patch or seal the rigid liner in any way once it’s damaged. Fiberglass patching kits used for automotive purposes aren’t fish safe and make ponds chemically contaminated. They also tend to fail early after being submerged underwater. Sealants and tapes sold for repairing plastic rigid liners suffer from the same problems. It’s hard to get materials to stick to the rigid surface well enough to create a watertight seal. Most rigid liners are replaced entirely every time they begin to leak. That adds up quickly considering cracks can form within the first few years of use.
Fish Safety of Sealant
Don’t try pour on sealant products designed to be used in pools or concrete fountains either. These sealants rarely adhere to the materials used for rigid pond liners and are usually unsafe for both fish and water plants. Clay sealants designed to deal with leaks in naturally lined ponds aren’t of any use with this situation either. The clay can’t bond with the plastic or fiberglass, thus preventing any sealing effect. Though damage is rare, quality flexible liners can repaired with a combination of adhesives and sheets of material or heat sealing equipment. It’s easy to find fish-safe sealants for these liners since they’re so widely used for commercial and residential fishponds.
Replacing Damaged Liners
When it comes time for removing and replacing a liner that has reached the end of its lifespan, consider the weight and size of the material you’re removing. A flexible liner can last decades before needing replacement. Though, when necessary, it is easily cut into pieces, folded up, and carried out by hand no matter how large the pond. Even a 200-gallon preformed pond liner is often too heavy and cumbersome for an individual to lift by hand without equipment. Not only is replacement of preformed products much more difficult, it will also be required much more frequently. Do you want to bring in lifting and towing equipment just to get rid of a damaged old pond liner when it’s time for a major repair?
Consider the process of repairs and maintenance when planning out your pond project. Make sure you choose a reliable product like AquaArmor from BTL Liners.
