Re: How to put a new floor over a cement floor covered with tar
What you've probably got there is called "cut back". Take a sample and go to a flooring supplier that supplies to contractors, they will be able to identify it and provide you with a solvent that is designed to remove it. I had the same thing in my garage and it's a nasty mess. Apply the solvent as per the instructions, let it do the work, then scrap the gooey mess up and put it into a heavy garbage bag or bucket that you can put a lid on to keep it contained.
You will want to wear something you won't mind throwing away when you're done, I'd even recommend plastic booties for your shoes (plastic grocery bags work well ) and absolutely wear rubber gloves and eye protection. This stuff is going to get everywhere, no matter how careful you are HOWEVER try to be as careful as you can so you don't make a mess everywhere.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!