Hi - first post to the forum but I've been gaining lots of useful advice before tackling 30msq of reclaimed oak parquet. The question I need an answer to is what is the maximum height difference I can expect to be able to "sand away" during the first 40-60 grit pass? I ask because I'm in the process of dry laying and acclimatising the cleaned blocks before bonding and there is quite a height difference (+2-3mm) between some of the blocks - will this much sand down or do I need to get rid of the high blocks before laying?