Pond Liner Sizing and Installation Guide
A base should be prepared for all surfaces to be lined. The base should be free of sharp objects, rocks, roots, plants and organic soils. The base should be smooth and free of depressions or protrusions. Fine soils, such as sand, clay or dirt are acceptable for lining. For coarser soils, a layer of GN200 8 oz. Green Geotextile should be placed beneath the liner. The edge of the lake or pond should be prepared as follows:
Laying down the liner
Once the liner is delivered and inspected, remove the banding and outer cover. It may be necessary to CAREFULLY cut the geotextile wrapper to gain access to the bundle. Do not cut the bands on the liner itself at this time. Once the bundle has been exposed, the top of the liner should be labeled with 2 dimensions with directional arrows. The first number and arrow signify the length and “unroll” direction. The second number and arrow signify the width and “unfold” direction.
Example: 100’ ↑ X 68’ →
This signifies that your bundle will unroll 100’ and then unfold 68’. Place the liner at the appropriate location in a corner of the pond and unroll in the direction of the arrow 100’. Once the bundle is laying flat along the ground, have all available helpers spread out evenly and pick up the top/leading edge, and pull the liner across the pond (68’). It is recommended that you place people at a minimum of every 15-20 feet along the edge, deploying evenly across the pond.
Securing the liner
While working, the liner can be held in place with sand bags. Then, the top edge can be secured into an anchor trench. It may be secured with 6” long steel staples. Do not firmly secure the top edge of the liner until the pond is at least half full, since the liner may need to shift during filling. If materials, such as sand, gravel or rock are to be placed on top of the liner, a layer of GN200 8 oz. Green Geotextile should be laid down first. Sand bags can be used to hold the geotextile in place until covered. If covering materials are only being place around the shoreline of the pond, the pond should be at least half filled with water before the materials are placed.
Joining liner panels
If multiple liner panels are needed for a project, the use of liner tape is acceptable for joining the panels if done correctly. The taped sections of liner must be clean, dry, free of folds or wrinkles, and above 50°F. Overlap the panels to be joined by one foot. Place a continuous strip of 2” double sided liner tape between the overlapped pieces and secure. Then secure the exposed liner flap with a continuous strip of 4” single sided liner tape.
Penetrating a liner with a pipe
Pond liners can be successfully penetrated with pipes, however only smooth-walled (not corrugated) pipes may be used. Pipe Sleeves are used to join the liner to the pipe. Select the appropriate size sleeve and install as follows:
- After installation of pond liner, carefully cut hole to allow pipe to slide through liner. Allow liner to fit flat on ground.
- Slide boot over pipe and push down to pond floor/wall, etc.
- Carefully cut boot flange base so that it exceeds the cut in the liner by 4 to 6 inches in all directions. Make the flange square.
- Clean liner and flange. Use water, MEK, Xylene, etc… Do not use soap.
- Mark a line around flange and remove boot.
- Place 2" wide double sided tape on liner (bottom view drawing). Be sure to overlap at corners by 14". Leave film layer on the top of tape. Use a rag to firmly press down the tape and work out any wrinkles.
- Replace boot, remove protective covering and press down on the tape and work out wrinkles.
- Place 4" single sided tape completely over edge of boot, centering on the seam.
- Place band clamp on boot riser approximately 1" from top of boot. Tighten and cover with 4" single sided tape.
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