29 undermount bathroom sinks from Toto (10), Duravit (7), American Standard (7), Gerber (2), Elkay (2) and DXV (1), in vitreous china and stainless, oval and rectangular, 15-3/4" through 22-5/8".
The vanity top decides whether an undermount lav is possible. The basin hangs from the underside, so the cut edge of the top is exposed and has to be stone, quartz or solid surface — something that can be polished and sealed. On a laminate vanity top the core sits open at the cut and swells, and the sink has to be drop-in instead.
The faucet does not mount on an undermount lav. It mounts on the counter. Decide 4-inch centerset, 8-inch widespread or single hole before the top is templated, because the holes are drilled in the stone and cannot be moved afterwards. Two of the Toto basins here carry their own deck drilling instead — the LT587 at 4-inch centers and the Atherton LT221 at 8-inch.
Most of these basins have an overflow, and the drain has to match. A sink with an overflow needs a pop-up with overflow ports; fitting a solid grid drain to it seals the overflow channel and the overflow stops doing anything at all. A sink without an overflow takes the grid drain.
Toto’s CEFIONTECT is a ceramic glaze fired into the surface so waste has less to hold onto — the difference shows on a basin that gets cleaned weekly rather than daily. Duravit runs the Starck 3, Vero, DuraStyle, No.1 and Design Classics series here; American Standard the Ovalyn, Studio, Studio Carre and Boulevard; Elkay the Asana in brushed stainless.
Related: undermount kitchen sinks, pedestal sinks, wall-mount sinks, vessel sinks, consoles and vanity top sinks, bathroom sink accessories and the full bathroom range.
