A pond constructed of wood is typically built using sleepers that are stacked similarly to the way that a log cabin is constructed. This provides a solid, sturdy framework in which to install the pond. A pond of this type fits well into almost any outdoor landscaping theme and is ideal for sloping lots. A raised pond has another important benefit. It is much more difficult for toddlers to gain access to the pond if it is built higher than they can reach, making it a much safer landscape pool than a pond that is built level with the ground.
Dig out the ground in the area where you intend to install the pond until you have a level surface on which to work. Use the framing level to check that the ground is sufficiently level. This step is unnecessary where the ground is already flat. When installing the raised pond, you can place the timbers and plastic over the grass.
Place the first course of sleepers into position as the base of the square pond. Build the first course so that the lumber of the second course will overlap the ends of the wood on the first course, enabling you to bind the overlapped corners in place. Join the wood of the first course together using 8-inch galvanised nails hammered in at an angle.
Build up the courses of the pond, overlapping the ends of each sleeper until you have reached the depth that you want for the pond. Join each course's boards together using the galvanised nails, and then use the same nails to secure the ties on top to the ties below. Because the inside of the structure will be the pond, while the outside will be visible, nail into the inside of the structure only.
Fill the base of the structure with sand to provide a soft bottom for the pond liner and to help prevent tears to the plastic. If you wish to have tiers or shelves in the base of the pond on which to place plants, put leftover pieces of sleeper into the bottom of the structure.
Lay the pond liner into the structure, and then begin filling the polyurethane with water. This will allow the bottom of the liner to conform to the inside corners of the structure without tearing.
When the pool has filled with water, staple the edges of the pond liner to the top of the uppermost sleepers, and then cut away the excess pond liner with a razor blade. Cover the cut edges with the treated 2x4 lumber to hide the rough edge and nail them in place to complete the pond installation.