what would be best.

[dylan_30]

Hi all, I have a bathroom conversion going on. At present I have 18mm chipboard (green) on what I believe is a floating floor.
Now I have already made the decision to tile on my floor and in doing so Im going to remove the old chipboard as it has got wet.
What I want to know is am I better to put chipboard back in and then use a 6mm backboard panel like no more ply,hardibacker or aquapanel.
or would you suggest something else.
I know this has probably been asked 20 times but to get this computer of my wife and search is nigh on impossible.
thanks for any suggestions
dylan

 

[Ian]

Can you be sure that it is a floating floor? Are there definitely no joists under the chipboard?

 

[dylan_30]

ah good question and shows my amateurishness. Um no not until I take it up, although I think there will be joists. If it helps it is a new build bungalow.

what would be your advise either way.

 

[Rich]

I would recommend removing the chipboard and strengthen the floor by adding noggins to the joists while you have the floor up. Replace with min 15mm WBP ply (the thicker the better), use as few sheets as possible, leave 2-3mm between each sheet and the sheets should be staggered. Also seal the underside and sides of the sheets but no the top surface. Screw the ply down to the joists at a min of 300mm centers (the better screwed the ply, the better the floor). Then over the top of this over board using a cement board, glued and screwed down. This will give you a brilliant floor to tile onto. The most important thing to remember is to make the floor as solid as possiblt and remove any deflection BEFORE you lay the cement boards.

The link below might give a bit more info

[h=3]Plywood floors...[/h]

 

[Rich]

ah good question and shows my amateurishness. Um no not until I take it up, although I think there will be joists. If it helps it is a new build bungalow.

what would be your advise either way.

I would assume that it is a suspended floor rather than a floater.

 

[dylan_30]

thanks for your time rich. Hopefully the floor will be suspended then. Can I ask why you leave the gap, Im guessing to allow for thermal expansion etc

 

[Rich]

Yes, ply will swell and contract with any change in moisture, even from the room below. If the boards are butted together, the ply swells and lifts the tiles and it is a pain in the back side to sort out after the floor has been tiled.

 

[dylan_30]

just read your post and found it really helpful, now going to check the best places I can find some ply. going to go with 18mm I think as that's whats down now then overboard with cement board, do you have any preference on cement boards.

Glad ive looked into this as it would have all been back up in a few weeks otherwise.

 

[Andy Allen]

before you go spending your money, i would check to see if the floor is on joist, or is a floating floor, pull up the carpet and see if nailed or screwed down...

 

[dylan_30]

ive already pulled up the carpet and there is no screws in it.

 

[Andy Allen]

sounds like a floater, is it quite bouncy when you walk on it..

 

[Gall.B]

I prefer Hardie Backer as far as Cement board goes.

 

[dylan_30]

no not much movement in it, just a little and some damp boards from a leak and over bath shower. Thanks for board recommendation gall.

Trying to decide between hardie and no more ply but dont know of a stockist for nmp where as topps have hardie.

 

[dylan_30]

need to check flooring first though as I might need a new plan if its a floater.

Dont think my wife is going to be happy with how long tis room takes me

 

[Andy Allen]

if its a floating floor then i personally wouldn't tile it without installing joists first...