On Jun 21, 6:25 pm, Harlan Messinger
wrote:
Why is a solid backing needed behind a pedestal sink? The pedestal does
support it, doesn't it?

It's not an either/or situation - the sink is supported by both the
wall anchors and the pedestal. There are sinks designed for anchoring
into a wall only (some very cool, highly stylized ones, too), but I am
unaware of a free-standing pedestal sink that doesn't require some
sort of attachment to a wall.

Considering the pedestal, though, can only effectively handle direct,
downward weight, you need solid anchoring into the wall to handle off-
center forces such as when someone leans on one side of the sink and
the like. Toggle bolts into drywall will certainly not handle it, nor
will doing so into plaster (or plaster over lath). To ensure a sink
that will last you forever without needing remounting, I would
encourage some sort of refit behind the wall of a cross-piece between
your studs. It's messier, more complicated and a bigger pain in the
neck than maybe you want, but the work will pay for itself in peace of
mind.

And like so many DIY jobs, this also is one where you get what you pay
for. The higher priced sinks I've seen have better designs for
anchoring and much better pedestal-to-sink fit to ensure a stable
installation than do the bottom-tier set-ups I've seen (and bought) at
the BBS (big box store).