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Floor patterns. Each block not only has its own ceiling slab but also its own foot slab. The "foot slab," as we call it, consists of a rectangle of stone strips of varying width. They are lying on top of the concrete floor. The pattern of these rectangles, their geometry, is not identical to that of the ceiling slabs; it is made visible on the floor by changing the direction of the stone and varying the patterns from field to field (see the black plan, page 100): large fields separated by joints, a right-angled mosaic.
The floor plan above studies the relationship between the ceiling joints that cast shafts of light on certain walls (yellow lines) and the floor joints that conduct the water (blue lines).
Water flows in the joints of the floor. All of the drains and overflows required to operate the baths are worked into the linear pattern of the floor mosaic, including the overflow of the pools. The early sketch to the right shows the basic idea: the water flows over onto the top step of the stone stairs leading into the pool. The resulting film of water laps over into a joint in the stone floor from which it runs off (see the detail of a built drain on page 110). Thanks to this overflow detail, we were able to fulfill a long-cherished wish, one that had arisen while we were still working on block studies and stone models: pools filled with water up to the rim and flush with the floor, no shadow frames around the water's edge!