• You also have to dig a not too deep foundation pit, which must be compacted. In order to have the bottom of your pool, to have an even surface, the thickness of which will be 20-30 centimeters are poured onto a tamped earth, and then again ram. After the sand is compacted, it will be necessary to lay a waterproofing layer in the form of a roofing material or bitumen to the bottom of your pit.