I recently removed a parquet hardwood floor that was installed at some point in my home before I purchased it in 2003. While taking the tiles up wasn’t difficult I did find a tar substance that was put down under them to hold them onto the subfloor. I’m due to have a new white oak character grade solid wood floor laid on this subfloor and my installer wants to charge me $400 to remove the substance before the floor goes down. I don’t have an issue paying but if there’s a way for me to remove it myself and save some $$ I’m willing to do it. I do t really want to use any chemicals and found online someone used a wall paper steamer to heat the tar and the scrape it up and then wipe down the subfloor with a sponge and vinegar water. I have the steamer on order to be here Friday but I wanted to ask before I do this, will I cause any issues for my subfloor and moisture before the new floor goes in on April 30th? Think it would be possible with running a dehumidifier and the house AC that I would be ok with trying this? Or is this all just a bad idea and I should just wait for my installer to use his machine to take it all off (17” Diama-brush plate)?

You do not want to deal with that mess. Trust me. Just because one person supposedly did it this way...

Spend the $ 400.

Thanks, I was already leaning that way. Was just curious. Solid advise right there!