Pond liners are revolutionizing water gardening. They are a major part of state of the art technology in pond construction.
Thank goodness for the advent of quality, inexpensive liners; for their use in waterproofing ponds waterfalls and streams.
Though various types of liner materials have been around for decades, the latest wave of inexpensive PVC liners are responsible for bringing on the water gardening boom.
Vinyl (PVC) liners are becoming much more readily available, less expensive and therefore common as: Underliners of concrete basins or as the sole water-tight membrane making up basin/s, stream/s & waterfall/s. This overview piece describes the application and installation of liners in waterscape construction and urges you to include them in your feature.
History of Liner Use:
Starting in the late 1950's in Western Europe and the United
States, a new material, polyethylene (Polythene, visqueen) started to be marketed and used for pond building. In sheets and in semi-rigid forms this material is to this day used by some people for the following reasons: It is inexpensive, readily available in several colors and thicknesses.
On the downside this plastic is relatively flimsy; easily punctured, difficult to repair and fit with plumbing and takes a beating with exposure to the elements, especially sun light.
"Poly" liners can be used effectively as concrete underliners or under soil to slow down degradation. Due to their short-lived-ness, polyethylene liners are less and less used as PVC liners have become more widely known and less costly.
Butyl rubber liners became more popular in the "60's", though they've been in use since the 1940's as reservoir liners. They have the longest life (50+ years by some estimates), are beautiful, and easy to install. Their major drawback is their higher cost (about two, three times PVC, but dropping).
PVC; Poly Vinyl Chloride:
Poly-vinyl-chloride (PVC) liners are by far the most appropriate liners. They are of wide availability and moderate price, come in several stock sizes; in colors of gray, black, green and clear in various thicknesses. They are easy to install and fit through with plumbing and electrical & last for at least ten years. Custom sizes are easily seamed together in sheets.
Per your site selection, size and shape aspects of your pond allowances for drainage, run-off, utilities and maintenance needs to be provided for. Do your homework at the planning stage by reading & talking enough with people in the know until you feel comfortable with the project before purchasing and installing your liner.
Layout the perimeter of the excavation with a rope or hose until all parties involved are in agreement. Mark the area off with chalk or stakes & dig a hole or build an above-grade form.
Measure the finished hollow of the basins and secure an adequate size liner; one with a good 6" plus overlap over all edges. Using a string or rope, laid down along the ground is useful for measuring.
Make sure the liner is PVC and of at least 20 mil thickness. The overall best thickness for liner-only ponds are 32 mil Tetra brand. Smooth out rough spots, rocks, roots in the basin before laying in the liner with sand, carpet, newspaper or other material to reduce puncturing and wear. Warming the liner in the sun for a while makes it more flexible/manageable for installation.
Place a garden hose in the middle of the liner and slowly fill, all the while checking the perimeter for enough overlap. While filling, smooth out large creases by folding and stretching the liner. When filled , trim off, or better still, roll and tuck the extra liner over the edge. This excess may be further secured with mortar, rock, wood or soil.
Concrete Ponds and Liners:
Our Construction Division, Aquatic Environments, used to employ PVC liners under concrete basins and water falls they built as a first and last line of defense against leakage. The common practice is to attach the liner to the berm (edge) made up of a perimeter of rebar and up and over the trough of the waterfall(s) and streams if present.
Reinforcing mesh, welded wire are laid in and attached to the edge as well. Electrical conduit and plumbing are laid in the basin and concrete is hand-packed, pumped, shot-creted or gunited in depending of the size of the system and the finish desired.
The small added cost of the liner in this operation is more than offset by the security against leak damage.
Puncture, Tear Repairs:
If they should occur are easily repaired by drying and cleaning the area with solvent and attaching a patch of the trim material to the area. Test your solvent for compatibility; there are some produced just for this purpose.
Pieces of liner may be joined in together in a similar fashion. See particular manufacturer's instructions for their suggestions.
PVC liners can be very useful in other ways. As pond covers, shades; and very importantly as repair membranes for systems that are leaking, cracked, have broken basins or with questionable plumbing. These can be remedied with using a liner over everything as if the basin were just a hole in the ground.
Allison, James; Ponds past and present; Practical Fishkeeping, March 1987, p. 78-79.
Cole, Peter. 1990. Koi; freshwater revival Barnhart, Earle. 1994. Garden ponds that work; new details con
trol overflow and build reliable edges. Tropical Fish Hobbyist 3/94.
Debelius, Helmut. 1985. The PVC-liner pond- homemade. Today's Aquarium- Aquarium Heute 3/85.
Heritage, Bill; It'll never catch on, part II; The Water Garden Journal, Vol III, No. 1, March 1987, pp. 10-15.
Orchard, Wayne & Susan Boland. 1990. Construction of a koi pond with a vinyl liner. Koi USA 3-4/90.