Hello all. I'm not a flooring guy, more of a grease monkey. I've installed duraceramic which went well but had a pro lay carpet upstairs. Now the wife wants me to put the carpet tile she bought in the basement which I think I can handle. I've removed all the old crappy carpet which was glued direct to the concrete. The den and Hall was glued entirely while the bedroom was only glued partially. My question is about removing the old yellow glue. Does it all have to come off to the bare concrete? Can I scrape off what I can leaving what won't scrape without hardcore effort? I have about 500sq ft. The carpet tile I'm putting down is felt backed and I have Shaw 5001 pressure sensitive adhesive. Thanks in advance.