The steel rebar is installed in a grid pattern. Depending on the loads and soil condition, it can be 12" apart, 6" apart, or in rare cases 3" apart. Our civil engineers work out the exact pattern to be used for your pool and this is part of the engineering required for your pool permit and for our structural specifications. The steel is blocked 2-3" off of the excavated floor and walls of the pool. It greatly strengthens concrete by providing tensile strength. Be careful, although we cover or bend the ends of the bars to protect people, the wires used to tie the steel together are very sharp. Please insure the safety of children and pets. A scratch from the steel or tie wire can infect easily and may require tetanus vaccination.