On 5 Aug, 19:42, "Paul Moore" wrote:

I'm looking for some advice on how to protect a wooden floor from scratches
and marks caused by furniture wheels.

Use the right floor varnish. The two-part acid-cure ones that stink
during application are far harder than polyurethanes.

I was thinking of replacing the sofa's nylon wheels with softer rubber
wheels, but will they just mark the floor instead?

Use non-marking synthetic rubber wheels. Most are grey, some are even
black, this is a common problem with a well-established solution now
and decent wheels shouldn't either indent or leave rubber smears.