"Paul Moore" wrote:
I've just sanded my living room floor for the second time in 10 years, this
time because of the tracks caused by hard nylon sofa wheels and the brass
wheels from a heavy grand piano. Can anyone offer any advice here on how to
prevent this problem happening again?
[...]
For the piano, I don't know what to do, any ideas?

You could try castor cups but probably the only thing that'll work is
replacing the tiny brass castors with a proper A-frame support with
decent sized rubberised wheels. This is more the kind of thing you'd see
at a concert hall or school, of course. Reduces the strain on the
spindly legs when you push it around, as well.

Downside: it doesn't look as good and the piano will end up somewhat
higher.

Ask at a piano shop, or look at this page:
http://www.igotmusic.co.uk/results.asp?cat=PFOTH