There are two types of tubing in concrete, embedded and pour over.

Embedded concrete is typically used in basements and garages. a vapor barrier is installed over compacted fill. Then foam insulation is added on top. The oxygen barrier tubing is laid out and fastened to the foam insulation with staples. The concrete slab is poured and the final flooring of choice is installed over everything.

Pour over is used on a subfloor such as plywood and then concrete is poured encasing the tubing. The final flooring finish completes the project.