Adding a coat of urethane

Q: We are moving into a house where the wood floors were totally redone after the prior owners moved out. Our inspector suggested that because we have a dog and small children that an additional coat or two or urethane may be wise.

How much can I expect to pay for this, and is sanding between coats necessary?

A: I would think you should expect to pay at least $0.75 for a polisher buff and 1 coat of finish. Buffing a previous older coat of finish on surface is generally required to gain adhesion. The new coat of finish adheres to the scratches that the buffing creates. There are solutions created by some manufacturers that chemically prepare the old coating to accept another. I have not used them to date, but they are somewhat costly also.