I have a sanded wooden floor in a bedroom which I originally treated
only with danish oil. I like the mellow matt effect which this gives,
but the room is going to be changed to use as a living room, and the
floor will start to get more wear which I don't think the oil alone
will withstand. Is it OK to varnish over the oil? In other heavy-use
rooms I've used "diamond hard" floor varnish (by Ronseal as I recall)
which is water-based. Can you put a water-based varnish over a floor
treated with oil or should I find some oil-based varnish?