First Question: Is the House Even on a Slab?

In a town where the oldest homes stand on piers and the later ones sit on concrete, the same symptoms point to two completely different jobs. The quick tells: a slab home has its floor at ground level with no crawl space vents in the skirting and no access hatch anywhere, while a raised home sounds hollow underfoot and shows daylight or vents at the foundation line.

Getting this right matters because a warm floor over concrete means a pressurized line has failed beneath it, while the same symptom over a crawl space means something far easier to reach. We confirm the construction in the first minutes of the visit, and the rest of the diagnosis follows from it.