Post category: Water Features

 

Garden pools

 

Water is restful and reinforces a garden’s air of calm and tranquillity. A pool of some sort can be chosen to suit most gardens. Concrete pools are difficult to build and often crack. Ready-formed fibreglass is quick and easy to install, but unless well disguised, it tends to look artificial.

 

 

Water Features
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Pool liners of polythene, PVC or butyl rubber are cheap, easy to put in, and can be made to any size or shape – except formal. Estimate the size of the liner as the maximum length plus twice the maximum depth and the maximum plus twice the maximum depth. Leave a little extra as a precaution.

Dig a hole to the size and shape required. The depth should be 45 centimetres for a small pool, 60–75 centimetres for a large one. A ‘shelf’ to one side, about 20 centimetres deep, is ideal for marginal water plants. The sheet to fit the hole should be the maximum length plus twice the maximum depth, and the maximum width plus twice the maximum depth. Line the hole with a layer of sand; spread the liner; weigh down the edges with bricks or stones, and fill the pool with water.

Around the edges of the pool, the polythene, or PVC, must be hidden from sunlight or it will break down and crack. Usually a pool is associated with a paved area and the paving could be laid to overhang the liner.

 

Cascades and streams

 

Cascades, waterfalls or artificial streams can be made with flexible pool liners that take the shape of the excavated soil when they are filled with water. A cascade of little ‘waterfalls’ can be made by having the water fall down a series of overlapping small pools. Unless there is a clean fall over the edge of a stone, water can be lost as it trickles down the face of the step between the small pools. Alternatively, the face of the cascade could be lined as well.

An ‘artificial’ stream can be made of a series of long narrow, shallow pools. In this case, and for cascades, it is essential to hide the liner with sand, gravel or stones. Any sight of the liner destroys the effect of these natural-looking garden features.

 

Formal pools

 

Formal pools are always of regular geometric shape, usually straight sided but sometimes circular, or semi-circular. A flexible liner cannot be maintained in a regular shape without rigid support. Concrete is used for formal pools but they are tricky to build without cracks.

The hole is dug out with straight sides and lined with heavy polythene. A solid slab of concrete, well tamped down and perhaps reinforced, is laid in the bottom. As it begins to set, the surface scum is brushed off the edges where the walls will be built. These must be built the following day and the floor kept damp in the meantime.

 

 

Water Features
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The walls are built of dense blocks with joints of strong mortar and rendered with strong sand and cement plaster. Split blocks or bricks could also be used, without plaster rendering of course. Bonding adhesive can be mixed into the mortar and rendering to increase the bond and help to seal the walls.

Two days later the space between the walls and the polythene lining is filled with general purpose mix concrete, well compacted all round. The edges of the pool are finished with large paving slabs. The concrete surfaces of the pool can be sealed with special pond sealers, painted on.

Alternatively, the pool can be built as described but a flexible pond liner is placed under the pool base. The walls are then built on the base and the liner brought up behind the walls and filled behind before the edging slabs are put in place. The liner seals the pool and the concrete sides give the required formal shape.

 

Plants

 

Water lilies need deep water, and remember to get some oxygenating plants, such as Canadian pondweed or water milfoil. As these compete with algae for nutrients, they prevent it from clouding the water. Plenty of oxygenators are needed in a new pool.

 

 

Water Features
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A cascade fed by a submerged circulating pump can be a great addition and is simple to install. Make a concrete course for it to flow down, or else use stones. Strips of pool liner could be used too, but they look a little obvious.