Floor Tiles Lifting On Anhydrite Screed

[Ajax123]

Soloflex is not gypsum based. If its wet under the tiles it probably wasn't dry in the first place. It maybe that water has got in afterwards but in my experience this is much less likely.

 

[Ajax123]

I've done one that has failed had reps out from Kerakoll, Mapei and the company that installed the floor. In my opinion nobody has a clue the product seems to be unstable, I ended up going with Kerrakol Eco h40 I think(memory lacking) it was mineral based floor a abraided and vacuumed as recommended. Six months later failed or should I say failing. Fortunately the contractor took responsibility for it because I refused to do it because it wasn't fully dry in my opinion.
Done another one recently but gone for Mapei adhesives as per there recommendations installed on ditra then if it does fail the floor should hopefully stay in position. Gyvlon, anhydrite what ever you want to call it "walk away" nothing but trouble.

Blimey...its been a while since I heàrd that phràse

 

[AD Ceramics]

Blimey...its been a while since I heàrd that phràse

Which phrase it that pal.... 90m2 floor.... Is there an expansion joint in the flow screed/gyvlon-anhydrite? Then there is no point in the the tiles, even more so if a de-coupling mat... That's my opinion. Controversial maybe

 

[Ajax123]

It was the walk away nothing but trouble comment.... I've not heard that for ages. It's not trouble unless you don't know how to deal with it. Reference your joints comment I always say that just because the screeder hasn't done his bit properly why would the tiler want to cut corners. If the standards say a joint is needed then put it in. At least that way if it does go wrong you are able to say it ain't your issue.
I think realistically though if an anhydrite screed has no movement joint there should still be one in the tile face as the tiles and adhesive are likely to move much more than the screed. Ditra certainly helps but its not always needed.

 

[AD Ceramics]

It was the walk away nothing but trouble comment.... I've not heard that for ages. It's not trouble unless you don't know how to deal with it. Reference your joints comment I always say that just because the screeder hasn't done his bit properly why would the tiler want to cut corners. If the standards say a joint is needed then put it in. At least that way if it does go wrong you are able to say it ain't your issue.
I think realistically though if an anhydrite screed has no movement joint there should still be one in the tile face as the tiles and adhesive are likely to move much more than the screed. Ditra certainly helps but its not always needed.

I understand what you are saying, I know how to deal with it, or I thought I did. I don't cut corners, the new builds I do the floors in say a kichen for example may range from 60-90ish m2 do you think the developer/client wants to see and expansion joint through there 200k-300k kitchen.
And if the screeder hasn't done his job properly where do you determine the floor will crack? If I am carrying tiles through in to other areas I put expansion joint in a doorway that's a typical place for failure.
I know tilers, developers, builders that have followed the correct procedure for anhydrite screeds and they have failed, and I know ones that have disregarded the procedure and they're stuck solid and not had issues, why is it so unpredictable? Your a screed advisor.....your thoughts please.

 

[J Sid]

I believe that a anhydride screed should have a expansion joint at 20mt max length with a heated screed and will expand 8mm over that length, correct me if I'm wrong @Alex123. And the tiles expanding about 4.5mm over that length.

So the tiles will need a movement joint or 2 over that length, and if the customer doesn't want any then walk away as it will more than likely fail at some point in the future. If it still fails then the tiler can say 'its not down to me' as @Ajex123 says.

Movement joints though floors don't always have to be unsightly.

 

[Ajax123]

I actually haven't come across an instance where tiles have failed that I have been unable to explain. I have been to a lot where the explanation is not acceptable to the client or the tiler. I hear the phrase "i did it by the book" and " i used all the recomended materials" so often i have lost count. To be fair lack of joints in either screed or tiles is way down the list of issues. The most common is moisture. I.e tiles put down too soon and that is followed by or usually goes hand in hand with the use of acrylic primer and cement based adhesive. Thing is with anhydrite it doesn't behave anything like cement board screed in terms of shrinkage, movement or cracking. Not to say it never cracks....it does sometimes. Certainly the number of failures has plummeted since the advent of gypsum based adhesives and since Francis flower came into the market as a binder supplier and we offered advice at all stages of the project we have seen a lot of failures avoided. One of the biggest issues I find is the lack of knowledge not so much amongst the tilers but amongst the adhesive manufacturers. I still hear reps saying that you have to grind off the top 5mm or you have to scabble and that laitance keeps àppearing after the tiles are laid. All of these are wrong.

I developed the attached data sheet to cover flooring contractors and they have been generally well received. I think they are helpful but am happy to readdress it if you tiling types think they're not

Information Guides

 

[Ajax123]

I believe that a anhydride screed should have a expansion joint at 20mt max length with a heated screed and will expand 8mm over that length, correct me if I'm wrong @Alex123. And the tiles expanding about 4.5mm over that length.

So the tiles will need a movement joint or 2 over that length, and if the customer doesn't want any then walk away as it will more than likely fail at some point in the future. If it still fails then the tiler can say 'its not down to me' as @Ajex123 says.


Movement joints though floors don't always have to be unsightly.

Maximum bay length is indeed 20m. The level of movement depends on a number of factors. The coefficient of linear expansion is 12x10 to the power of -6 m per m per kelvin. In other words if you start at 15degrees c and you increase the temperature of the floor to 25degrees c it will expand by 10 x 0.000012m per linear meter (so x20 if its 20m long).
In other words not a lot.

To meet the British standard there should be movement joints between independent zones, where hot meets cold and across all door thresholds. These are not often put in and it rarely actually causes an issue.

 

[J Sid]

@alex do you or other suppliers of this product offer a "signing off" ready to tile service?

 

[Ajax123]

@alex do you or other suppliers of this product offer a "signing off" ready to tile service?

No. It is something we discussed some time ago but realistically we don't have the manpower. There are Six of us working for Francis flower binder division. We supply to around 80 depots and each of these could do an average of two jobs a day. We were always happy to respond to enquiries from tilers and clients and often do. We also try to maintain relationships with suppliers of suitable adhesives as well. We do what we can but like any low staff company we can't do everything. I personally take calls from probably 3 or 4 tilers a week. We also supply specification advice to clients which is fine for bigger clients like the major house builders and where tyhjis has happened we don't get issues. Unfortunately though there are so many jobs thgast we don't get to intersect with we can oknlky hope to help by making the right information easily availkable usually through internet. I been on here for wages as well which I like to imagine helps a bit.

 

[Ajax123]

Oops... I meant i been on here for ages....not wages,.. Chance would be a fine thing eh

 

[J Sid]

@Ajax123 Thanks for yours replies.
So an opening for someone with the right knowledge / training to go round all these job and sign them off as fit and ready for the covering to be applied.

 

[AD Ceramics]

I actually haven't come across an instance where tiles have failed that I have been unable to explain. I have been to a lot where the explanation is not acceptable to the client or the tiler. I hear the phrase "i did it by the book" and " i used all the recomended materials" so often i have lost count. To be fair lack of joints in either screed or tiles is way down the list of issues. The most common is moisture. I.e tiles put down too soon and that is followed by or usually goes hand in hand with the use of acrylic primer and cement based adhesive. Thing is with anhydrite it doesn't behave anything like cement board screed in terms of shrinkage, movement or cracking. Not to say it never cracks....it does sometimes. Certainly the number of failures has plummeted since the advent of gypsum based adhesives and since Francis flower came into the market as a binder supplier and we offered advice at all stages of the project we have seen a lot of failures avoided. One of the biggest issues I find is the lack of knowledge not so much amongst the tilers but amongst the adhesive manufacturers. I still hear reps saying that you have to grind off the top 5mm or you have to scabble and that laitance keeps àppearing after the tiles are laid. All of these are wrong.

I developed the attached data sheet to cover flooring contractors and they have been generally well received. I think they are helpful but am happy to readdress it if you tiling types think they're not

Information Guides

Is that not you want to hear "I did it by the book" or to the required specification.
Laitance removed, underfloor heating commissioned moisture tested correct adhesives etc etc etc, 90m2 kitchen floor no joint required unless it's a very narrow kitchen!!!(theoretically a corridor over 20m)
Explain what would cause it to fail, even you confess failures have plummeted since the introduction of gypsum/mineral adhesives, so there's still failures.
Stop trying to blind us with science........who is this Kelvin fella

 

[wayne]

The solo flex from benfer is a calcium sulphate based adhesive.

 

[widler]

Is that not you want to hear "I did it by the book" or to the required specification.
Laitance removed, underfloor heating commissioned moisture tested correct adhesives etc etc etc, 90m2 kitchen floor no joint required unless it's a very narrow kitchen!!!(theoretically a corridor over 20m)
Explain what would cause it to fail, even you confess failures have plummeted since the introduction of gypsum/mineral adhesives, so there's still failures.
Stop trying to blind us with science........who is this Kelvin fella

Even when the tradesman said he did it by the book, they can still blame it on something else, the problem is no matter what trade you are in if it goes boobs up the material manafacturerer will ALWAYS blame it on his mother brother sister or uncle , but never himself , they have yiu by the short and curlies, hell they can prove it with big words