A.Tom Meehan, a
tile-setter who owns and manages Cape Cod Tile in
Harwich, Mass., with his wife, Lane Meehan,
responds: There are two ways to approach
tiling a room with radiused walls. I think the
old-fashioned way — a mud job done with
wire and cement — is best. With this
approach you need a layer of felt paper, galvanized
wire mesh, a scratch coat of cement, and then a
full coat (around an inch) of cement; it requires
the skill of a professional tile-setter experienced
in mud-bed jobs.
The easier method is to apply two layers of
1/4-inch cement backerboard to the framing over a
layer of felt paper, staggering the boards at the
joints and bonding them together with a thin coat
of nonlatex thinset mortar spread with a 3/16-inch
V-notch trowel.
I recommend using USG's Durock 1/4-inch-thick
cement board (800/874-4968,
www.usg.com), which seems to
bend more easily than any of the other brands of
backerboard. Even so, you'll need all the help you
can get to hold it in place, so I would use one of
the special cement-board screws instead of nails to
fasten it to the framing.
To get a smoothly curved surface, good framing
is important, too, preferably with the studs placed
no more than 6 inches on-center.