Pools can be either dug into the earth, or built above ground.

When excavating, make sure that the design is finalized before digging commences. Virgin ground is much more stable than fill and so if the pool can be dug in a single operation, it can save enormously on construction costs, especially if Firestone Pondgard EPDM liners are used.

Virgin soil will remain stable at 45 degrees from the horizontal if soft sand, 60 degrees if loam and can even be excavated vertically if pure clay. But be careful with pure clay as it will change dramatically between dry and wet conditions. Only a flexible liner like Firestone Pondgard EPDM will work in clay, unless a very solid steel and concrete shell is built with proper engineering drawings.

One of the biggest costs with excavating is the removal and dumping of excavated soil. Once excavated, soil will expand by approximately 1.5 times its volume. So try to find appropriate places on your property to use the soil without needing to remove it from the site. This can be used to create a water feature or fountain.