Loose Floor tiles :( New Floor

[Southside691]

got an issue with 2 bathrooms I've just had tiled. So the issue is with the floor tiles which happen to be the same ones I have on the wall and are fine. The issue is that the tiles in both bathrooms have become loose and the grout has started to come away. Now the tiler has been round twice to rectify the issue but it's still there. I've spoken other tilers who I've asked to come round to fix the issue and some have suggested that the floor which was made up of cement board screwed to the joists needed a primer before the tiles went on and the other guy saying that he would have gone with ply. The cement board that was used looked like some generic board which was really heavy and had some sort of semi shiny covering on both sides. The builder who prepared the floor with the cement board said he screwed it down well and the adhesive used was UltraTile Proflex SP+ES bagged.

Any advice?

 

[J Sid]

has the adhesive stuck to tiles but not floor or floor and not tiles ?

 

[Time's Ran Out]

As a Tiler I want to prepare the substrate prior to tiling. That means adhesive and mechanical fixing of cement boards ( Hardie not shiney boards) taped joints and flexible adhesive. Now you have to determine who is responsible - builder/tiler.
Certainly don’t agree with your ‘tilers’ choices of preparation, Hardie doesn’t need priming and Plywood is not suitable as a finished over boarding material.

 

[Flintstone]

I've never seen a shiny board before? If it is a cement board, the bond to that with that adhesive is very strong. Could be movement in the sub floor ?

 

[J Sid]

I've never seen a shiny board before? If it is a cement board, the bond to that with that adhesive is very strong. Could be movement in the sub floor ?

may just be tiles not stuck to adhesive

 

[On one]

I've never seen a shiny board before? If it is a cement board, the bond to that with that adhesive is very strong. Could be movement in the sub floor ?

'Shiny',could be refering to NMP?

 

[hmtiling]

I hope it's not 12mm direct to joist. The 22mm nmp is good stuff and the adhesive mentioned is one I use very often without issue. Could be no priming. It will suck the life out of adhesive very quickly ruining the bond

 

[GoneGuy]

Sounds like no more ply boards?
Did the builder use adhesive under the boards to fill any voids?
Sounds like no primer used and dusty surface which could cause the tile to de bond

 

[Southside691]

I think the board that was put down was a generic hardiebacker board and it was supplied by the builders merchant. All I remember is that you cut it the same way as plasterboard with a Stanley knife. The builder is happy to pay for the works but I just want to be sure, this time it's done right.

Thanks

 

[Boggs]

I wonder if it was 6mm Knauff Aquapanel, that has a shiny top side and cuts with a knife.

 

[On one]

A bit of confusion going on here. ......you can't cut a cement based 'Hardiebacker' type board with craft knife.
You can cut an insulated 'cement coated polyurethane 'Wedi','Marmox' type board with craft knife

 

[hmtiling]

I think the board that was put down was a generic hardiebacker board and it was supplied by the builders merchant. All I remember is that you cut it the same way as plasterboard with a Stanley knife. The builder is happy to pay for the works but I just want to be sure, this time it's done right.

Thanks

Cut with a Stanley knife sounds like coated xps, which topps say on their website can go direct to joist. It cannot and will fail. You need to find out exactly what thus stuff is

 

[hmtiling]

I wonder if it was 6mm Knauff Aquapanel, that has a shiny top side and cuts with a knife.

Apparently this board is direct to joists

 

[Boggs]

Oh yeah,
Direct to joists and cuts with a Stanley knife, not sounding good is it...

 

[Waluigi]

I originally thought it was a shiny XPS but the OP said it was a heavy board which adds even more confusion into it.

 

[J Sid]

it's all guess work

 

[macten]

Is NMP shiny now? Never used to be.

 

[bolts]

No NMP isn't shiny, must be something else.

 

[On one]

My thinking was that NMP was shin(ier) that Hardiebacker which has a matt finish.

 

[Southside691]

I think you guys might be right, looking at pics on the web it did look like NMP.

So if the NMP wasn't primed beforehand, would this be the reason for them becoming loose? The builder says it's not down to movement as he screwed the board down really well. Really strange that it's happened in 2 bathrooms on different levels. What would be your advice before the tiles are put down? primer and same brand adhesive or would you suggest something else?

 

[Dumbo]

I think you guys might be right, looking at pics on the web it did look like NMP.

So if the NMP wasn't primed beforehand, would this be the reason for them becoming loose? The builder says it's not down to movement as he screwed the board down really well. Really strange that it's happened in 2 bathrooms on different levels. What would be your advice before the tiles are put down? primer and same brand adhesive or would you suggest something else?

Can you just clarify is your cement board (If that is what it is ) fixed directly to the joists with no floor board underneath or is it fixed to the joists through the floor boards .

 

[Southside691]

The cement board was fitted on top of the existing floorboards in 1 bathroom and the other in the loft has ply below. Cement board glued and screwed down builder tells me.

 

[Waluigi]

The problem with overboarding is that sometimes people do it just to tick the box- overboarded.

Before overboarding the existing floor needs to be checked throughout to see how stable it is. How much deflection and mainly how well screwed down it is. Also when overboarding chipboard, the overhang of the chipboard needs to be checked. Some floors just aren’t suitable for overboarding.

 

[Viceroy]

One side of NMP is shiny now as it's pre-primed

 

[hmtiling]

Were the boards glued at the seams also?

 

[J Sid]

has the adhesive stuck to tiles but not floor or floor and not tiles ?

I've asked this question and had no answer as yet.

if you answer @Southside691 we will be more able to say what's happen.

 

[Southside691]

Sorry guys but I need to take the tiles off before I can tell you that so hopefully soon

 

[J Sid]

thank you @Southside691 when you do that that will give a better idea of the root of the problem, until then it could be 101 different things

 

[Southside691]

Sorry for the delayed reply, but with the lockdown in force, I've had time to have a closer look at this. So it seems that the tile has been fixed to the Hardie board dot and dab style So the plan is to remove, clean and prime, dittra mat and then tile. Any recommendations on the adhesive I should use? Porcelain tiles. Thanks