In the middle of updating the bathroom on a 60's house and wanting to use ceramic tile. Original construction was 2x10 @ 16"oc; 6" T&G (3/4 thick) installed on a 45 deg angle, with 5/8" plywood over that - and carpeted...... Rearranging fixtures so had to remove the plywood and replace some of the T&G now need to know what to use on top of this to use ceramic tile. Also considering installing some floor heat in the walk track (Northern MN). Thanks for any and all assistance.