Limestone / Hardie / Chipboard ?

[tomo13]

Hi, I have some limestone to do soon and was wondering what would be the way to go ? The guy has had the existing chipboard replaced with new chipboard. I was then going to fix Hardie Backers (can use either 6mm or 12mm) to get the floor nice and solid. My main question is should I also use Ditra or would the backers be ok on there own ? Thanks for any replies.

 

[Gazzer]

I would use ditra with stone.
Just make sure the floor is free of any deflection.

 

[Qwerty]

I would use ditra with stone.
Just make sure the floor is free of any deflection.

^^ As above ^^

Also, for info, the 12mm Hardi is really for walls, but I am sure you already knew that

 

[peckers]

you say you can use 6 or 12mm hardibacker to beef up the floor, as sir ramic has said make sure the floor is free of deflection first as Hardi isnt used to beef up the floor it is used to give a suitable stable background to tile to. And I would use ditra too.

 

[Rookery]

6mm Hardie plus membrane for me too.

 

[tomo13]

just for future reference, can Ditra / Dural be laid on top of old tiles before laying new ?

 

[Qwerty]

just for future reference, can Ditra / Dural be laid on top of old tiles before laying new ?

In a word......No

 

[cm ceramics]

Use 6mm backer boards and membrane

 

[White Room]

Use 6mm backer boards and membrane

On existing tiles ???

 

[cm ceramics]

On existing tiles ???

It doesn't state in the original question that it was to be laid on top of existing tile as far as it states that the old chip board has already been replaced.
Not a fan of tiling over tiles, would always remove as you can never be sure of stability aspects

 

[cm ceramics]

Ahh sorry [MENTION=1504]whitebeam[/MENTION] just read through the full post there and I never seen the post for future rereference.
Can see why it could be misleading

 

[White Room]

Ahh sorry @whitebeam just read through the full post there and I never seen the post for future rereference.
Can see why it could be misleading

No problem, that was the post obviously that caught my eye

 

[cm ceramics]

Well spotted, better noticed than it being misinterpreted by someone else

 

[tomo13]

I have seen this on the Schluter website on the data sheet.

Balconies / terraces
As an uncoupling membrane, Schlüter
®-
DITRA 25 neutralises the stresses between
the substrate and the tile covering that are
caused by the frequent and extensive temperature
changes occurring on balconies.
Furthermore, Schlüter
®-DITRA 25 serves as
a bonded waterproofing assembly together
with the tile covering (see notes on waterproofing).
The substrate (concrete, screed)
must be sufficiently sloped.
For refurbishments, the existing surface
assembly can generally remain, provided it is
sufficiently sloped and load bearing. Prior to
the application of Schlüter
®-DITRA 25 over
existing and cracked tile floors, the loose
tiles must be removed and the remaining
cavities filled using an appropriate mortar.
The preparations also include ensuring a
proper slope in the substrate.
We recommend Schlüter
®-DITRA-DRAIN
(see product data sheet 6.2) for coverings
with side lengths exceeding 30 x 30 cm


Is it me or does it read that you can on to existing tiles or is it different because it is on a balcony or terrace ??????????????

 

[Qwerty]

Yes, you are right.....Schluter do state this, but as you say only for balconies & terraces. The exterior pavers on balconies & terraces are usually very solid and often bedded into/ onto the waterprofing layer. I wouldn't ever dream of following suit internally though

 

[tomo13]

Have been told by Schluter tech that as long as the floor is even and load bearing it can go on old tiles. But am I willing to take the risk ??????????????? it came across like it was a bit of a standard reply from them.

 

[tomo13]

Also have now spoken to a guy at Dural and he said, as long as the adhesive will bond to the substrate be it tiles, steel or whatever then Durabase is excellent for those types of situations. it might seem like I am trying to talk myself into it, but it would be very handy if in the future I don't need to take tiles up if they are solid and the customer wants me to go over them and there are no height issues. I always prefer to take them up but as you know trying to get tiles up that are stuck with 2 part is no fun.

 

[AliGage]

Im interested to know how any tiler could offer any guarantees of non-failure going over an existing tiled floor if you have no idea how that floor was laid and by who.

 

[Qwerty]

Im interested to know how any tiler could offer any guarantees of non-failure going over an existing tiled floor if you have no idea how that floor was laid and by who.

My thoughts exactly Ali

 

[tomo13]

As I said in my post, I prefer to take them up. But if a customer is adamant that they are staying and they are solid, no signs of cracking, loose tiles or damage etc. Then it would be interesting to know if these products are designed for these kind of scenarios, and this is what I am trying to find out by contacting the tech depts., as these are the people that should know ?

 

[Stef]

As I said in my post, I prefer to take them up. But if a customer is adamant that they are staying and they are solid, no signs of cracking, loose tiles or damage etc. Then it would be interesting to know if these products are designed for these kind of scenarios, and this is what I am trying to find out by contacting the tech depts., as these are the people that should know ?

"These are the people that should know"
Yes they should but I would take what they say with a pinch of salt.
I foned Mapei technical about a Gyvlon screed & they told my that I don't have to bother with the screed being 75% RH & below as that's only for carpet & wood coverings, not tiles!!

 

[AliGage]

The only person that knows the condition of the current installation is the tiler that fixed it. In my opinion.
Lost count of the amount of times I've removed what looks like a sound floor but once pulled at the tiles all delaminate easy.
I don't tile on tile as a rule because i can offer absolutely no guarantee that the floor Im going over won't fail.

 

[widler]

I've used 12 and 6mm on a 50m floor,in some areas I've had to double up.
Some timber and some concrete.
It now all feels like a solid floor,I know they say the addy underneath the boards is for voids ,but it does defo does make it more solid feeling ( and I don't mean it stops it bouncing)

I would tile over floor tiles no problem,if they were solid,it's quite easy to check,hammer and bolster ,have a crack at taking up,of they come up in ikkle pieces ,tile over them,if they come up easy take em up.
It ain't rocket science .
You all tile over a plastic membrane,which the tiles stick to ,it's plastic ,so why would tiles not stick to a solid tiled floor ?