Plate question for closet built on concrete slabs

On top of the linoleum tile PT plates are really not necessary. As long as there's no history of moisture seeping up through the floor or frequent mini-floods from inattention to laundry sink blockage or some such. Having said that, would I use PT plates? Probably.

The major disdvantage nowadays is the ACQ chemicals used in PT lumber. It's much more corrosive to standard fasteners and you should use either stainless steel, epoxy-coated or galvanized fasteners that specifically list their suitability for ACQ contact.

Need? No. At least assuming that the slab is dry under all conditions.

But for the difference in price between untreated and treated it certainly shouldn't break the budget if it makes you feel better to use treated and down the line somebody may well thank you for your foresight.

Thanks for the replies.

If it was built in 1960, none of the other bottom plates are PT. I'd use regular 2x4's