UFH/ floor tileing

[johnatjdl]

Hello guys, my first post but I havnt had much time to navigate it yet, so hopefully this is in the right section. If somebody could give me some advice on the following I would be very gratefull.
I am a qualified plumbing and heating engineer with loads of tileing experience.
This is a project at home (bungalow with access under the floor, suspended timber floor,400mm joist centers)
- Spliting a big bathroom in toTwo. One an ensuite/wetroom, one stays as main bathroom.Both to be tiled and UFH in both. Using spreader plates, kingspan type insulation underneath.
Currently 22mm chipboard, obviously going in the skip, what type of flooring should I use that will take a tanking membrane and tiles, I am tempted to screw down 20mm ish marine ply or far eastern ply and tile straight on top. What do you guys think ?

Regards John

 

[swanman]

Go with 18mm ply a grade srewed 600 centers

Then i would go with a hardi backer board 6mm glued with a flexible adhesive then srewed

 

[Rich]

Min of 15mm ply (18mm is easier to get your hands on), seal the underside and edges, screw down at a min of 300mm centers, stager the boards and leave a 2-3mm joint between each board. Then over board with a 6mm cement board, screwed and glued.

Sounds like a lot of work but it is the best way to make those floors last. Have a read through the link below for a little more info on tiling directly onto ply

Plywood floors...

 

[peteablard]

What he said^^^^^^^ Couldn't have put it better myself Rich!!