Installing a flexible liner is easier than you think because the material easily spreads to cover the ground by hand. Rigid pond liners must be supported with a perfectly sloped and sculpted opening in the ground, while flexible liners conform to the shape you’ve made. Start the installation by carefully unfolding the rolled or folded liner material you’ve ordered. Slowly spread and stretch it to fit the opening of the pond, overlapping the material generously over the sides. Leave some slack in the liner until it’s been spread over all the edges of the pond. Then focus on straightening out the fit and eliminating as many of the folds and wrinkles as you can.
If you notice any areas where soil has shifted and left a void, take the time to pull the liner back and fill the space with more soil or expanding foam. Leaving voids under the liner, even if the space is only a few inches deep, will allow the material to stretch and shift. This could potentially tear the liner or pull it away from filters and pumps. If you stop installing the liner for more than a few minutes, used some weights like sandbags or buckets filled with water to hold down the material without damaging it.
