"in2minds" wrote
| I'm considering 2 options, both result in having a chipboard
| (can't remember the proper name)

flooring grade chipboard?

| floor, if only because of impact resistance (as apposed to concrete)
| if a child falls over

I wouldn't worry; it's extremely unlikely a small child would chip or
otherwise damage concrete :-)

For child friendly flooring, I would suggest cork sheet. Also good for
insulation. I've dropped plates on cork tiled concrete, and the plate
bounced unbroken.

Owain