What sub base for tiles

[Craigo007]

Hi. I'm after some advise. I am shortly going to be ripping out water damaged patchy chipboard flooring in our utility room. We have purchased the floor tiles ready for this. Can I use 25mm WBP ply fixed to the joists with noggins on the ends and tile straight to this or is this wrong. Any advise much appreciated.

 

[Ajax123]

Use 18mm ply but then overboard using 6mm cement based backer boards.

 

[Andy Allen]

Are you sure it's on joist and not a floating floor..?

 

[Ajax123]

Good point Andy...

 

[Waluigi]

Nah, he has joists

 

[Waluigi]

Quite unusual on a downstairs having chipboard with joists. Actually good point and worth checking

 

[Craigo007]

Hi, thanks for your replies. It is a ground floor extension that was done by previous owner. It has 6x2 joists with a 12" space to the ground with supports spaced out. Sorry I'm not sure is this classed as floating. The room is only 2.1 x 2.8.

 

[Ajax123]

lots of floating floors are placed on battens which to a novice could be mistaken for joists.

 

[Ajax123]

Not a floating floor then.

 

[Craigo007]

Thanks. I've just read something about sealing the underside of the ply. What's the reason for this and does the ply need priming for adhesive to bond to.