A rigid pond liner is important for pond design because it provides a barrier against the intrusion of water and sediment, which can lead to odors, algae growth, and decreased water quality. Additionally, rigid pond liners provide an aesthetically pleasing surface that can be used to create a landscape or garden feature.
Here are the 9 easy steps to install a rigid pond liner for your water garden:
Determine the required lining size.
To do so, double the pond depth by twice the length and breadth of the pond, then add extra 2 feet to ensure you have enough liner around the outer perimeter. Some liners may need underlayment under certain settings. The liner manufacturer will usually specify which liners need this protective layer between the liner and certain kinds of soil. Some liners, for example, need underlayment when used with rocky soil.
Using a rope or garden hose, draw the contour of your pond.
If you’ve already bought your liner, make sure you stay to the size and form you choose.
Dig out the shelves after removing the sod.
Most ponds are built with 9 to 12-inch deep shelves to house emergent water plants like those seen in our Bog Plants section. Make sure to make yourselves broad enough to accommodate an attractive planting. Narrow shelves restrict the quantity and kind of plants you may add later.
Excavate the pond’s deeper region.
The sides should slope in at roughly a 20-degree angle from the verticle. Using a board and a spirit level, ensure that the pond’s bottom is level. If you put a drain in your pond, make sure it is in the deepest part of the pond and that the bottom slopes slightly in that direction. Cut a ledge 1 to 2 inches deep along the whole perimeter of the pond for edging material using a flat spade. This will assist to conceal the edge of your liner and keep it in place. Check that the pond’s margins are level. If you don’t have a long enough board to reach across your pond, you may use a line level instead.
Prepare the hole for the liner by removing any stones, roots, or sharp items and filling it with 2 to 3 inches of sand.
If necessary, apply the appropriate underlayment for your liner at this stage.
Attach the liner.
Insert the liner into the hole with care. Fill up the gaps with a few flat stones or bricks. If your design includes a waterfall, lay the waterfall liner along the whole route of the cascade, overlaying the pond liner. Begin filling the pond with water. While it takes time to smooth out as many wrinkles as possible in the liner, some will remain. After the pond has partially filled, you may remove the weights you used to keep it in place; if they are too near to the edge, they may be drawn into the pond as the liner settles; nevertheless, be sure that the liner’s edge does not collapse into the water. You may begin to install your edging material after it is full and the liner has completely settled. There is no need to trim your edging material if it reaches over the edge of the liner. Long nails should be used to secure the liner along the pond’s edge, above the waterline, and under the final placement of your edging material. It is recommended to leave cutting off the surplus liner until the final phases of creating your pond in case you need to make modifications to the location or settling of the liner.
Finish with your edging materials.
Coping stones are often utilized for this purpose. Mortaring the stones in place is one approach to keep them from shifting and falling into your pond. Place stones to give a natural appearance on waterfalls. Place stones strategically to form ‘jumps’ for the water to flow over. This adds to the waterfall’s movement and sound.
Mortar comes in bags and is widely accessible at any reputable hardware shop or sand and gravel yard.
There are also dyes available to make the mortar appear more like earth and less like cement. An inexpensive, disposable 4-inch paintbrush works well for tamping the mortar into the joints between the stones.
Decide the level of the liner.
When constructing the waterfall, take in mind that 1/2 inch of water equals 10 gallons of water per minute on a 12-inch wide weir. Keep this in mind while you build the spillways and purchase a pump. If your pump cannot pump enough water to cover the weir you built, the weir will look completely different than if the water covers the full weir. Sheets of water need a substantial supply of water at the drop-down location. Also, if you want to grow plants in the pools in the stream or waterfall, or on the weirs, or if you intend to restrict the flow of water at a certain location, make sure that the liner extends high over the level of the weir and around the whole pool.
Trim away any extra liner and finish with some elegant landscaping around the perimeter of your water garden.
Ensure that fertilizer run-off from your landscaping or grass does not enter the pond and generate quick green water. You may begin to put your water plants after treating the water to eliminate chlorine or chloramine. Some individuals prefer to let the water mature before planting or adding fish to their ponds.