I have resently been given over 40 boxes of parquet flooring which was taken out of an old building there is tar on the back and I have been reading some of your comments on how to clean this of ie; freeze and chip off. I know this is going to take along time in parparing them to lay again would you say this was the most effective way a my mother in law has offered to help. Would you also sand each block down. My father has a large bench sander could they be done on this one by one (I know time consuming but he is retired. Any help would be most welcome. Thanks.iris4050