How can I fasten baseboard over concrete?
Either could work.
I've also used trim-head screws in plastic plugs for base trim over concrete. That would involve pre-drilling to mark screw location, then drilling the concrete and installing the plugs, then screwing on the trim. The holes would be larger, but that's mostly a problem if you're using stained trim.
Of course you could fur out the wall to create a more standard backing situation. You'd lose 1-1/2&quot; of room space.