To an outsider, the job of an out-of-ground, or on-grade, wall may seem easy enough — it just sits there. But this type of wall has a special function: It must withstand pressure from water inside a pool without having soil on the other side to equalize it. And with no earth to back it, an on-grade wall requires special construction techniques.

The key to an on-grade wall’s success lies in the planning, forming, steel and concrete. Here’s how to give them the care they need during the four-stage construction process