Once the size and position of the pit is determined, start to excavate the selected area to about 200mm below the grass or finished sand level (see Fig 2). You can use the top layer of grass to repair bare spots in the lawn, or stack it upsidedown in the compost. Dig out the dark-coloured top soil and add to compost or scatter in the garden. Prepare a flat bed for the sand to sit on (see Fig 3). If your subsoil is clay or hard pan you may face drainage problems. To overcome this install a perforated drainage pipe, drain tile or a deep hole in the middle of the pit and then cover with crushed rock, stones or coarse gravel and replace soil.