Ditra on Anhydrite

[Gazzer]

So if you were using the Ditra over Anhydrite/Gyvlon type screeds what adhesive would you be using to fix the mat down with ?

 

[DHTiling]

Flexi cement based.

 

[Ian]

Only done this once Neale, used Creative Impressions GBTA to stick the mat, still sanded, hoovered and primed the floor first though.

 

[Ajax123]

GBTA or gypfix prepped as normal

 

[Gazzer]

Does anyone know Schutlers word on this ?

 

[DHTiling]

Do schluter recommend that type of adhesive.

I did read they did not..

 

[bugs183]

I asked them on the Substrate Training day and they were very cautious, they favoured an Ardex cement based adhesive.

 

[Gazzer]

Do schluter recommend that type of adhesive.

I did read they did not..

Yeah thats what i thought too.

 

[Gazzer]

I asked them on the Substrate Training day and they were very cautious, they favoured an Ardex cement based adhesive.

was that a SPF or standard ?

 

[Dougs Third Go]

it's a bloody minefield,wish they'd all sit round a table and thrash it out:mad2:

 

[DHTiling]

I have no qualms about tiling to anhydrite with cement based adhesives.... ..


So far anyway :lol:

 

[Ajax123]

Schluter favour Ardex as they have tested this themselves. They have never tested gypsum adhesives as far as I know so would not be able to comment which would usually come out as a negative recomendation.

However to be fair if the screed is properly dried and properly prepared there is no reason why a cement based adhesive should not work. I remain (as I have said many times before) uncomfortable with the level of potential risk based on experience.

 

[Gazzer]

it's a bloody minefield,wish they'd all sit round a table and thrash it out:mad2:

Yup Get them all singing from the same Hymn sheet.

 

[DHTiling]

Yup Get them all singing from the same Hymn sheet.

Will never happen .. they are all frightened to commit.

 

[Ian]

A I right in saying that Schluter recommend a contact adhesive to stick the mat down? Be it on anhydrite or S&C? Or have I just made that up! It would make perfect sense if the glue bonded to the screed.

 

[Gazzer]

Will never happen .. they are all frightened to commit.

Never mind eh....leave it to the fixer to carry the can ! :mad2:

 

[bugs183]

I'll be honest Sir i instantly stopped listening as soon as they mentioned cement based adhesives as i don't trust them on this system, someone else can tile it.
Don't worry i'm not gonna start, i was just saying what Schluter advised!!!!!! :lol:

 

[Dougs Third Go]

Will never happen .. they are all frightened to commit.

maybe they're all builders?...."tiler will sort it out"

 

[Ajax123]

Will never happen .. they are all frightened to commit.

the issue is that as we (the binder suppliers) do not make the adhesives so we have no control and cannot take responsibility for how their gear is tested or how it performs. The best we can do is test the adhesives ourselves which has often been done. we are forced by the contracts and legislation that bind us to make relatively vague and wooly comments. i have advocated the use of gypsum adhesives for quite some time and am aware of very few failures where they have been used.

It is also unreasonable to say a cement adhesive wont work because here are lots of cases when it works fine. The majority of issues come when a tiler or a builder miss out a crucial bit e.g missing out joints, forgetting to moisture test, ignoring dust and dirt on the screed, failing to prep or a combination of all.

 

[Spud]

if you make the screed why dont you make a tile adhesive for it as well ?

 

[Mark S]

Everyone knows the correct prep for Anydrite screeds by now hopefully, sand and prime if using cement based flexible adhesives, sand and Kerakoll H40 Ideal, or the Creative Impressions version GBTA, I believe Kerakoll do a de-coupling nat so maybe worth contacting them.
I always think its best to try where possible to stick to 1 manufacturer
Mark S, Technical and Specification Manager, Gyvlon Ltd

 

[Gazzer]

Everyone knows the correct prep for Anydrite screeds by now hopefully, sand and prime if using cement based flexible adhesives, sand and Kerakoll H40 Ideal, or the Creative Impressions version GBTA, I believe Kerakoll do a de-coupling nat so maybe worth contacting them.
I always think its best to try where possible to stick to 1 manufacturer
Mark S, Technical and Specification Manager, Gyvlon Ltd

But Mark this is about what adhesive to use to stick the Ditra to an Anhydrite screed. Do any of those adhesive stick the Ditra?

 

[DHTiling]

the issue is that as we (the binder suppliers) do not make the adhesives so we have no control and cannot take responsibility for how their gear is tested or how it performs. The best we can do is test the adhesives ourselves which has often been done. we are forced by the contracts and legislation that bind us to make relatively vague and wooly comments. i have advocated the use of gypsum adhesives for quite some time and am aware of very few failures where they have been used.

It is also unreasonable to say a cement adhesive wont work because here are lots of cases when it works fine. The majority of issues come when a tiler or a builder miss out a crucial bit e.g missing out joints, forgetting to moisture test, ignoring dust and dirt on the screed, failing to prep or a combination of all.

That is the same for gypsum adhesives as well though..

Yes gypsum to gypsum is the more attractive route but adhesive comps are ripping the industry off with the prices they are charging.. material costs are no more for gypsum or cement IMO.. so why do they rip us off.?

 

[Dougs Third Go]

That is the same for gypsum adhesives as well though..

Yes gypsum to gypsum is the more attractive route but adhesive comps are ripping the industry off with the prices they are charging.. material costs are no more for gypsum or cement IMO.. so why do they rip us off.?

because (imo) if we don't pay, we get no comeback:incazzato:

 

[Ajax123]

if you make the screed why dont you make a tile adhesive for it as well ?

Thats my point Gary we don't make the screed. We just make the binder which is the "cement" bit. We (Francis flower) do supply quite a number of adhesive manufacturers as well though.

 

[Ajax123]

Everyone knows the correct prep for Anydrite screeds by now hopefully, sand and prime if using cement based flexible adhesives, sand and Kerakoll H40 Ideal, or the Creative Impressions version GBTA, I believe Kerakoll do a de-coupling nat so maybe worth contacting them.
I always think its best to try where possible to stick to 1 manufacturer
Mark S, Technical and Specification Manager, Gyvlon Ltd

would that it were true Mark that everyone knows the correct prep. I think it's fair to say most reputable and responsible tilers take the trouble to research it. The problem is not always the tilers though. There is some merit in the suggestion of using a pressure sensitive adhesive similar to those used for vinyl but I don't know of any specific research done by any of the adhesive manufacturers to ratify this.

 

[Ajax123]

But Mark this is about what adhesive to use to stick the Ditra to an Anhydrite screed. Do any of those adhesive stick the Ditra?

i have seen both used successfully although it is fair to say I have seen a few issues where the h40ideal has been used to stick ditra to a primed screed... David Howe was one such case.

 

[Dougs Third Go]

is there a rapid set gypsum adhesive?, I've always used rapid set for ditra/uncouplers just for the reason that if you need to pull a tile your're not going to pull the mat up too. I remember Dave having issues with, I think, kerakoll addy and uncoupling mat.

 

[Gazzer]

is there a rapid set gypsum adhesive?, I've always used rapid set for ditra/uncouplers just for the reason that if you need to pull a tile your're not going to pull the mat up too. I remember Dave having issues with, I think, kerakoll addy and uncoupling mat.

Gypfix is 3 -4 hours

 

[DHTiling]

is there a rapid set gypsum adhesive?, I've always used rapid set for ditra/uncouplers just for the reason that if you need to pull a tile your're not going to pull the mat up too. I remember Dave having issues with, I think, kerakoll addy and uncoupling mat.

Mmmmm