The Slab’s Own Map, and Where It Comes From  

Slab-on-grade construction has one defining fact, and the trade press states it plainly: Fine Homebuilding’s guide to plumbing under a concrete floor describes how the pipes are buried under the leveled pad and the concrete poured right over them, the rough-in laid out from the plans before the first wall is even built, pipes cast in stone from that day forward. In a custom home, that means every slab hides a one-of-a-kind layout.

In this city, it means the opposite: the plan’s under-slab routing froze identically in copy after copy, so where the hot line crosses to the kitchen, where the lines rise at the wet wall, and where the runs converge is knowledge, not guesswork. A slab leak here gets located with the map already on the table, the equipment confirming instead of hunting, and the mark on the floor earning a confidence most slabs never allow.