The new floor is only as good as what is under it, so tear-out is part of almost every job we do.
Carpet comes up with the pad, the staples and the tack strip. Tack strip nails left in the subfloor will push up through underlayment, so we pull every one. Old laminate usually comes up clean because it floats. Sheet vinyl and glued tile take more time, and we quote those after we see them.
One warning. Sheet vinyl and floor tile in homes built before the 1980s can contain asbestos in the backing or the mastic. If your house is that age and the old floor is vinyl or 9 inch tile, we will ask about testing before we disturb it. That is the rule, and we follow it.
Once the floor is bare, we scrape any old adhesive and vacuum the subfloor. Everything goes in our truck and leaves the property the same day. No dumpster in your driveway. Then we check flatness and move on to subfloor leveling if the floor needs it.