Remove old floorboards and replace with plywood

[Ashworth1]

I am re doing a bathroom that will be tiled. Would it be best to remove the floorboards and replace with 18mm plywood or just screw 6mm ply over the existing floorboards?
Thanks

 

[JP_]

Aquapanels, or similar that are designed to cope with moisture, might be best if you are ripping out the old.
What floor are you putting down? If vinyl sheet, and shower all properly sealed, then it should stay dry anyway...

 

[Ashworth1]

Was going to use porcelain tiles, can u put aqua panels direct to floor joists ? Thanks

 

[JP_]

Hmmm, not sure! My builders used Aquapanel in my ensuite in previous house, but cannot be sure if they were direct onto joists or over floorboards. I thought direct onto joists..

if they are like 12mm Hardiebacker boards, which I used in my new shower, they are bloody tough.