I am in the process of building a new room in a finished basement. I pulled up the old carpet, which was glued to the concrete floor. Scraping the foam off is a difficult and tedious task. How "clean" must the floor be before a new pad and carpet is installed?

You want to make sure the old padding has no clumps or you may feel them through the new pad & carpeting.

I greatly appreciate and respect your answers. I spent much time this weekend scraping down to the concrete. I wasn't sure if I needed a liquid cleaner to completely remove any trace of foam. As I run my hand across the cement, there are no clumps or high places. I should be in great shape and ready for the new pad and carpet!

Merry Christmas and God Bless!