My FH and I are currently debating whether we need to rent a wooden dance floor to put over the cement dance floor currently in place. Pros are aesthetics and a smoother surface for people to dance (though the cement is not bad). Cons are cost and the potential for slippage (the wedding coordinator said that she has seen several old ladies slip and fall on rented dance floors at this venue). This is a 22X22 cement slab. We would probably rent a 12x16 wood floor for 60 guests of we went with it.
