“I started more than 20 years ago working with concrete as an interior material,” says architect David Hertz. “At the time, it was a radical reaction to all of the faux finishes, and for me, slapping a big slab of concrete in the room was very real.” In the past two decades, Hertz has refined his techniques, even developing a patented lightweight, high-performance, and environmentally friendly concrete called Syndecrete. Hertz describes the material as “more akin to wood than concrete—more resistant to staining, cracking, or chipping—and it can be worked with woodworking tools.”
Water-resistant concrete works especially well in bathrooms, adds Hertz, and his innovative manipulations add eye-catching cachet to usually utilitarian spaces. Years of experience (and experiments) yield a bath portfolio filled with variations based on four types of concrete application: poured-in-place, pre-cast, tiles, and steel-troweled plaster. Integrated colors and textures ensure that no two baths look alike.
This Venice, Calif., master bath houses one of the architect’s first integral sinks. A series of pre-cast Syndecrete slabs, with integrated pigments, flow from vanity to backsplash to tub surround. The concrete backsplash appears to move right through the outside wall where it morphs into a balcony railing. Full-width glass on adjoining walls, in the form of a mirror and window, offers ample natural and reflected light. “The glass sits flush with the concrete,” Hertz says, “and you feel like you’re outside.”
“It was basically a box, so the question was how to do something interesting,” says Hertz of this remodeling project. The pre-cast bathtub blends the visual heft of a solid unit with the weight advantage of being hollow to facilitate waterproofing and plumbing. The shower may look equally seamless but actually consists of several joined slabs with a floating shower pan to conceal drainage. Grooves routed in the Syndecrete channel water runoff from glass partitions to the floor drain. Acrylic rods symmetrically embedded into a floor-to-ceiling wall panel were Hertz’s solution for transmitting light despite the home’s tight urban location. Exposed hot water pipes warm towels. Floor tiles and a plaster wall complete the concrete composition.
Heaviest as well as the most costly variation, poured-in-place concrete proves beneficial in some situations, as in this minimalist bath (bottom, right). “It’s monolithic and doesn’t require seams,” explains Hertz. “It can serve as structure and surface, plus it lends itself to whatever texture the forms leave behind.” A large steam shower with radiant-heat floors called for such watertight and heavy-duty elements. Exterior plaster walls wrap around to shape the shower and built-in bench. Fixed glass takes over fluidly where the concrete ends thanks to clear silicone and a stainless channel cast into the walls. Twin pivoting slits of glass offset the solid corner while releasing steam. A frameless glass door reveals Hertz’s planned illusion of the shower appearing to be carved from a single concrete block.
This airy beach bath isn’t exactly what comes to mind when Hertz talks about ways to use multiple types of concrete within one space. Sand-colored Syndecrete fixtures and finishes look more like stone than concrete. A pre-cast vanity has a purposefully shallow integral sink that causes water to splash outside the basin. A vertical slab dovetails into the thick counter so that sustainably harvested mahogany cabinets stay dry. The pale concrete then flows onto 6-inch square tiles lining the tub and shower. One-foot squares cover the floor. Stretching the tub into the shower produces two benefits. One is a roomy bench for sitting or for storing toiletries; the other is an overflow notch so the tub can be filled to the rim. Unpainted natural plaster walls with a wax coating complete the refined palette.
“There’s a primal nature to bathing,” says Hertz, “so I like to have a connection to the natural world.” Concrete with its chameleon forms, colors, and textures provides a tactile link while artfully placed glass does the rest. Naturally, the architect went one step further in his house. This all-concrete bath incorporates 10-foot-tall sliding glass doors that open up to a courtyard pool on one side and a narrow walled garden on the other. Exterior stucco turns the corner to sheathe the sink wall and ceiling while randomly set Syndecrete tiles back the shower. Clever uplighting turns the translucent sink into a softly glowing beacon.
