While I was watching the installation of the Endless Pool, I thought back to the beginning of the building of our new house. The first thing that was done was the digging of the pool pit. As you may know, this house is on a slab ... there is no basement. Because the pool itself was intended to be installed into the floor, the pool needed its own foundation to sit on. This is a photo of Norah checking out the beginning of that foundation ...
Gravel was laid into the pit and compressed.
A few days later, gravel was brought in (4 double trucks) and spread around the area where the house would be sitting. As you can see in this photo with Cooper, that gravel is about 16" deep.
On top of the gravel, two layers of four inch foam were added, increasing the height by another eight inches. The next step was to lay all of the tubing for the in-floor radiant heat (nearly a 3/4 mile of tubing). You can see the red squiggly lines in the next photo.
Following two layers of rebar, eight inches of concrete was added.
The floor is now at its thickest point of 34 inches. (16 inches of washed #2 limestone, 2 inches of pea gravel, 8 inches of foam, and 8 inches of concrete -- plus two plastic vapor barriers) . Once the carpenters have finished and the house is dried in, the concrete will be polished.