How to Build a Concrete Garden Pool
There are two types of garden pools, both of which are quite easy for the handyman to make. One is an informal pool, which is best suited to informal gardens. The other is a formal pool, rectangular in shape with clean-cut outlines.
The informal pool is simply made by digging a saucer-shaped hollow in the ground and excavating the soil to a suitable depth. Concrete is then mixed and spread inside the depression to a thickness of roughly 3 in. to 4 in. The cement for the concrete may be of waterproof quality, or the concrete may be waterproofed by adding a waterproofing powder. The surface of the concrete may be roughly shaped with a shovel, and the shape is then covered in the usual way with wet sacks or newspapers. The concrete is left to harden off for three or four days after which the covering should be removed. The pool is then filled with water.
A cross-section of an informal pool is illustrated right, which also shows a section of a formal pool. The formal pool is rectangular in shape, and the soil is excavated to the depth required. It should of course be appreciated that the site should be levelled.
The formal pool is made in two parts. The bottom or floor of concrete to a thickness of 3 in. is laid before the sides are made. A suitable mix for the concrete is one part waterproof cement to three parts sand; or Portland cement may be used, if waterproofing solution is added. The floor should be laid and smoothed over. To make the sides of the pool it will be necessary to erect formwork. If the sides of the excavation are firm and solid, it will only be necessary to erect inside formwork to allow a wall thickness of 6 in.
The method of fitting the formwork is illustrated above, and the inner surfaces of the formwork should be coated with lime-wash to prevent adhesion of the concrete. With the formwork firmly positioned, the concrete for the sides, which should be of the same proportions as the mixture for the bottom of the pool, should be knocked up and laid inside the shuttering. If it is not possible to mix all the concrete in one batch, each batch, as it is mixed, should be tamped inside the formwork. The level of the walls will be raised all round gradually, with succeeding batches of freshly mixed concrete.
Although the walls may be built up of separate batches of concrete all the work should be done in one day, and successive batches should quickly follow each other. The above illustration shows how the top edge of the pool may be finished with. The slabs are cemented in position to form an attractive edging that overhangs the sides of the pool.