Options when tiling over chipboard.

[Time's Ran Out]

FreeD - So what do YOU want to do!

You asked if it was okay to tile directly onto the chipboard floor after the deflection had been removed - NO.
You confirmed that 6mm backer board was the best option and it was confirmed it was - only onto a rigid floor.
If you want to replace the chipboard with 18mm+ plywood great but it should still be overborded or ditra matting before tiling for all the reasons previously given.
If its as serious a leak as you are anticipating - a river flood - the people wil move out, it'll take 6 months to dry out and the whole lot will be ripped out.

Timeless John.

 

[Perry]

You can tile directly to chipboard using 2 part green is not as good as the ordinary because of the wax but as Dave says you are best over boarding it ete

 

[CBTC]

In regard to deflection / stability of the floor, the hardibacker may not necessarily add enough strength, no. Its up to you to determine how much movement and lack of background stability there is. In my experience where chipboard boarding is put down it is rarely ever soundly done - and that's where it is for a floating timber or carpet flooring over it. For tile work its a non starter a lot of the time, and overboarding and sometimes augmenting the batten or joisting structure is required first.
Boards are determined by their constituentency and process really, hence chipboard cheap and weak. Exterior grade ply expensive and strong. Various in between. Thicknesses are specific to job and material type.
In my view overboarding this as you describe would be a must. Use of Fast Flex or Ardex 7001 type adhesivesisnt going to solve the substrate problems on their own!
Good luck.

 

[smurf21]

In short whatever timber substrate is down screw solidly to remove deflection then overboard with a 6mm cementious board following manufacturers guidelines.
if the floor gets wet and through the tile and grout it will not effect the cement board it wont rot and will not force the tiles to delaminate:drool5:

 

[FreeD]

Thanks all.

Given the customer option of securing existing chipboard floor then overboarding with 6mm hardibacker...mainly so good bond for tiles and to protect against water ingress from above.

or rip out chipboard and replace with 18mm ply.

Use 2 part flexible adhesive on both installations with flex grout.

In my opinion one of these 2 options in this situation will be fine.

I've checked out other products

plastic ply - useless technical support installed no confidence in me in the product...one thing i did get from my conversation is that the product is not suitable over chipboard of any kind even if it has been secured to the joists. And that only Nicobond adhesives and grouts should be used. He repeated this phrase about 10 times 'we cannot be held liable' lol

No more ply - looks good but has been discontinued by my local supplier and replaced with plastic ply, not sure why yet.

I'm sticking with hardibackers for now...tried and tested! :hurray:

 

[smurf21]

No more ply - looks good but has been discontinued by my local supplier and replaced with plastic ply, not sure why yet.

Its because GRUMPY GROUTER keeps doubting the magical capabilities of this amazing product:yikes:

 

[grumpygrouter]

Its because GRUMPY GROUTER keeps doubting the magical capabilities of this amazing product:yikes:

LOL...I don't doubt it is a good product Smurf. I am sure it is, but I can not get it where I am to try it so can not pass judgement by way of use. It MAY WELL have such magical properties that it will replace 15mm ply strength for strength, but it seems the company are too shy to provide detailed documentary evidence to prove it. The only reference they make in this resepect is in their marketing literature, which is designed to sell the product as best as it can, and it seems to be doing just that.

As i have previously said, if independent tests are carried out that verifies the claim and is reported as such in writing, I will be the first to push the product in these forums as it could be the life saver scottish timber frame houses need for safe tiling.