Preformed Pond Liner & Landscaping Designs & Installation Tips

Do you have you visions of turning your pond landscaping designs into successful projects? Building backyard ponds using preformed ponds built into the ground is easy when you pay attention to some basic rules and tops. If you are contemplating building a water garden or a backyard pond for yourself using a built in preformed pond liner then here is the way to make sure your pond landscaping designs work out in practice. Many preformed pond liner instalations can be placed aboe ground these days making the job much simpler. For now we will deal with the in-ground preformed pond liner.

  • preformed pond liner shape Place the preformed pond liner in position and mark out the shape on the ground around it.
  • Carefully remove any turf within the shape and excavate to a level soil surface slightly larger than the shape. A long spirit level, or a spirit level with a long straight edge is essential.
  • Excavate the shape of the preformed pond liner down to the same depth as the marginal shelf. Then make it one inch deeper (25mm) and 4 inches (100mm) larger all around.

  • preformed pond liner check level Check the hole is level, particularly around the edge.

  • Place the preformed pond liner in the excavation in its intended position  and mark with a sharp stick or trowel the shape of the bottom of the preformed pond liner in the soil.
  • Remove the pond shape and excavate to the full depth of the preformed pond liner plus an inch (25mm). With a bit of adjustment the preformed pond liner will fit like a glove, albeit slightly too large. The preformed pond liner should be sitting just below the level you had intended.
  • Remove the preformed pond liner and spread a layer of sand one inch thick over the base and the marginal shelf areas.
  • Put the preformed pond liner back in. Ensure the base is firm and level and there is solid support under the marginal shelves. Start to fill it with water.

preformed pond liner fill with water Whilst the preformed pond liner is filling, push sand into the gap between the preformed pond liner and the soil. The level of this backfill must go in unison with the water filling the pond and the pressure at which it is pushed in should correspond with the pressure from the water in the pond. This is a balancing act in which the sand or water could distort the shape. One German manufacturer used to recommend washing the sand into place in order to consolidate it. Doing this presupposes that the excavation is in fairly well drained soil and that you do not to get carried away with the backwash, otherwise the preformed pond liner just floats out of the hole.

Whatever method in landscaping designs you use, leave the pond there full of water over night to do any settling that might latterly occur, before you attempt any edging. If it shifts - empty it and build up the sand support where it has sunk. Gently ramming down the backfill further at the lowest point can make up tiny fractions in subsidence. If you need to do this dont overdo it because it can buckle up the rim of the preformed pond liner, which you want to keep as flat as possible to take whatever edging you might want to choose to go round it.

Take a look at Peter May's Perfect Pond Recipe book .... available by download or print and full of self explantory sketches

How to decide between preformed pond liner and flexible pond liner to suit your landscaping design ideas

Preformed pond liner considerations ...

  • Size limitation. Even the largest sizes of plastic preformed pond liners are difficult to install level. 
  • Very large fibreglass ponds are heavy.
  • Preformed pond liners seem easier to install in loose uneven ground. For the very large fibreglass ponds, installation is not a one-person project.
  • A preformed pond liner is easier to keep clean but can look sterile and plasticy in a natural environment.

Flexible pond liner for consideration in landscaping designs

  • Flexible pond liner can be used for any shape and any size
  • Flexible pond liner installation need a skeletal framework of blockwork or concrete to cope with loose soil or uneven ground.
  • Flexible pond liner can be made to look more natural by facing the inside with rockery. You can even line it with soil.
  • Marginal plant shelf can be where ever you choose.
  • Easily incorporate such features as jetties, decking, stonewalls, brick or wood facing and beaches.