Floor prep - TilersForums.com

[Woody123]

Hi all

Doing a job for the father in law at the weekend and he insisted on doing the prep to hellp me out! Anyway the original floor is 18mm weyrock floor i think and he has overboarded it with another 18mm tongue and groove chipboard. I have checked the floor is screwed down properley and there is no movement in the slightest. I have never used this stuff before as i have always overboarded with ply. Does anyone else ever go down this route as i asked how much he paid for it and it was only £5.69 for a sheet of 2.4m x 0.6m from B & Q so it was alot cheaper than ply. Im happy there is no movement so will this be ok to tile to? As it is not the norm for me am i just being paranoid? (By the way im just laying ceramics and will be using a flexi addy and grout)

 

[murf]

I would never tile onto chipboard, it can break down over time
no matter what adhesive you use.

 

[brian c]

not the best substrate to tile to....should have used ply.

 

[grumpygrouter]

Solidity is the main issue with floors IMO. Some guys on here will not tile directly to chipboard no matter what as it can be a bit unstable. Ideally, 18mm ply would have been better but as you say, it is more expensive. You can use an appropriate adhesive such as Ardexflex 7001 or maybe Mapei Keraquick with latexplus but really, you would be better overlaying with 6mm hardiebacker first. Tjhs get around some of the instability issues of chipboard.

 

[Woody123]

I thought there must be a reason why i have never seen this method used. Is it just if moisture gets in it breaks down easy? I know he wont change it now as he has fitted his new bath and shower tray on top of it. Would SPF not be suitable for this job then grumpy? you have me worried now :mad2:

 

[cornish_crofter]

As someone who has repaired several chipboard bathroom floors, I would advise against chipboard as a flooring material in the bathroom in general, even the treated stuff.

Tiling it would IMO make the problem 10 times worse. If it were untiled the water in contact would have half a chance to evaporate or disperse. Tiling it just confirms its demise.

I did use a couple of pieces to stick a bath onto recently to deal with floorbaords in poor condition but that is under the bath and tucked out of the way of the accessable floor area. I would have prefered to use ply but this stuff was to hand.

I think you're going to have to sit your FiL down and have a chat with him over this. The chipboard needs to come up, and be replaced with ply. The stuff under his bath can stay.

 

[grumpygrouter]

Because chipbaord is made up of, well, chips....the board can breakdown and debond in a worst case scenario, as in when it gets wet because it can "blow". Ardex for instance say their adhesive is suitable and indeed, I have used it straight onto chipboard, albeit not in a bathroom. SPF (I am asuming you are talking BAL here) really isn't suitable. bal would recommend fastflex for chipboard. if it was me and I HAD to tile onto it, then I would opt for the Ardex or mapei Keraquick/latex plus solution. backerboard would be better though.

 

[Woody123]

Oh dear oh dear, he is not going to like it but i will have to advise him of the pitfalls as it is on my head if it fails really.
Im not looking forward to this!

Cheers for the input people as i wasn't aware of the properties of the chipboard flooring.

 

[Woody123]

Cheers grumpy. It could yet come to me having to tile onto it so your advice is greatly appreciated.

 

[doug boardley]

I fall into the category of "won't tile onto chipboard" seen addys over the years that say it's now possible to tile onto c/board; none that I know have fulilled that promise!