I have a 2,400 s.f. office that is 6 years old and has carpet that is glued to concrete floor. A friend told me that I need to scrape up the old glue and seal the floor before we glue the replacement carpet. He tells me that the new glue and the old glue can have a chemical reaction that creates an odor that will not go away. The carpet installer is insisting that he can just remove the old carpet and sweep the floor and glue the new carpet down. I need to know the correct way to install the replacement carpet.

Just trust the carpet guy. There's nothing wrong with what he's proposing. I've done thousands of yards of carpet just like that.