Planning to build a pool in your garden? Choose an open, sunny site that is within easy reach of the hose or other water supply. Here are the other things that you need to know about building a garden pool.
Choose a pool shape.
Rectangles, circles or kidney shapes are fine, but avoid crosses, narrow waists or dumbbells — they restrict the circulation of water in the pool. Mark out the shape on the ground with pegs and string or, if the shape is curved, with the garden hose pegged down into the shape you want. Outline the shape with a half-moon turf cutter or spade, and remove the turf.
Start digging.
The centre of the pool must be about 1m deep, but leave a ledge round the edge no more than 23cm deep to accommodate your shallow-water plants. Smooth all surfaces, being careful to remove sharp stones. Line the pit with 2 to 3cm of sand and smooth everything again. If you can’t make sand stay in place on steep parts of the sides, use thick wads of wet newspaper plastered into position like papier-mache.
Line your pool.
There are a number of materials available for this. Polythene is cheap but won’t last very long. Nylon-reinforced PVC, which is more expensive, will last about 10 years. The most expensive choice, butyl rubber, will probably outlive you.
To discover the amount of material you will need, measure the maximum length and width of the pool and add 60cm plus twice the maximum depth to each of these measurements. Spread the liner over the bottom of the pool and up the sides, leaving at least 30cm of overlap round the edge of the pool. Weigh the overlap down with bricks, and gradually fill the pool with water. The weight of the water will press and stretch the liner into the shape of the pool.
When the pool is full, cut around the liner, leaving about 15cm of overlap. Press and pleat the liner into any corners it hasn’t reached, and fill any gaps with sand. Surround the pool with ornamental stone slabs, so that they completely cover the lining overlap, and protrude a couple of centimetres or so over the edge of the pool. Tread everything well down, brush off the edges, and your pool is ready for planting. Always keep the pool full of water, for direct sun on the liner will rot it.
Instead of using a liner, many people prefer to use a preformed fibreglass pool shape. The latter is long-lasting, comes with ledges and curves built in. But it’s more expensive, and packing up the ground beneath to marry precisely with their bumps and hollows can be quite a chore. As for the old-fashioned method of lining the excavation for the pool with cement, that’s hard, heavy and messy work.
Whether you’re starting or maintaining a garden, it’s better if you get help from gardening professionals.