Anhyfix fail on ditra matting

[Chris Gibbs]

I've done quite a bit of research on this gypsum based screed. The results are quite alarming from a lot of experienced tillers.
today I fitted (or started to)200m sq of ditra using TM anhyfix adhesive. it goes down ok but then when you push the mat into the ditra all seems good.... until you come cack to it in an hour. all it does is leace the imprint of the mesh backing on the anhyfix tile adhesive. I literally didn't need to clean the ditra!
Anyway I phoned schluter helpline and they said to use primer 3;1 then again prime 1;1 when dry and use ardex cement based adhesive to get the right adhesion to both surfaces. This would have cost me in excess of 20k to fix if id not spotted the problem.
hope this helps some guys in the future regarding anhydrite screeds.

 

[Flintstone]

That is good info as I have a job at the quote stage at the moment which may require ditra over anhydrite. Did they tell you the anhyfix adhesive isn't suitable ? Are you going to use cement based adhesive ? Be careful

 

[Flintstone]

Tilemaster - Ditra And Anhyfix - http://www.tilersforums.com/threads/ditra-and-anhyfix.79783/

 

[Old Mod]

As with a lot of adhesives, 100% adhesion is not overnight.
It begins to cure over several days.

Try it.
Stick several pieces of Ditra down and pull them up one after the other one day later than the last.
You know what I'm failing to say.

I'm not sticking up for Anhyfix, in fact I've never even used it.
But I do know that Ditra can take days before it's fully fixed to the substrate, adhesive dependant.

 

[Chris Gibbs]

Zero adhesion... I'm following schluters advice and going with the ardex. Can't remember the exact one... x7 I think. I will post the primer and adhesives tomorrow.

 

[Chris Gibbs]

3rd photo is the adhesive on the floor.
4th is the matting after it's been taken up....zero adhesion.
This could have broken me! Cos the tiles cost 8k alone

 

[Chris Gibbs]

Tilemaster - Ditra And Anhyfix - http://www.tilersforums.com/threads/ditra-and-anhyfix.79783/

Shocking...

 

[Old Mod]

Shocking...

How so?

 

[Chris Gibbs]

How so?

Zero adhesion. It's should be stated more that it shouldn't be used.
Try it and see what you think.

 

[Old Mod]

Zero adhesion. It's should be stated more that it shouldn't be used.
Try it and see what you think.

Did you read that thread that was linked?
Only read after I posted, but found it interesting.
It's difficult to comment further, two reasons,
One I haven't tried it! Haha
Secondly it would sound like I was criticising you maybe, so I won't.
And just thank you for your review Chris, every one of them are welcomed and helpful, always.

Oh, I do have occasion to use it in Aug actually, so I probably will, and I'll come back and compare! 🙂

 

[Dumbo]

I very rarely put down ditra or dual and tile to it the same day as I learnt early on if you have to lift a tile the matting comes with it . No chance next day . Still wouldn't of worried to much as I believe ( please feel free to correct me if I'm wrong) Schluter first marketed ditra as a loose lay system that didn't require sticking to the background

 

[Old Mod]

Just like Ardex 'Jawbone' is now, it's a new product in the states.
Although it's not called 'Jawbone'here, and I'm pretty sure it's not by Ardex either!
Go figure! 😛😛

 

[Simons70]

In the end of day ditra is just a plastic.We try to avoid ditra and use Bal matting where is possible, lay down with Ardex 200.

 

[Chris Gibbs]

I very rarely put down ditra or dual and tile to it the same day as I learnt early on if you have to lift a tile the matting comes with it . No chance next day . Still wouldn't of worried to much as I believe ( please feel free to correct me if I'm wrong) Schluter first marketed ditra as a loose lay system that didn't require sticking to the background

I very rarely put down ditra or dual and tile to it the same day as I learnt early on if you have to lift a tile the matting comes with it . No chance next day . Still wouldn't of worried to much as I believe ( please feel free to correct me if I'm wrong) Schluter first marketed ditra as a loose lay system that didn't require sticking to the background

i do know that it needs to stick down to the floor upswing the matting as its main key, otherwise there wouldn't be any matting in on the back. That's not the issue though really, just trying to inform people about gypsum based adhesives on uncoupling membranes cos it can be expensive trying to remedy later on, especially with a new aga fitted on top haha

 

[Ajax123]

Never had this issue. Seen lots of anhyfix used with and without uncoupling. Have you spoken to tilemaster aboutnit to find out what went wrong?

 

[One Day]

I'm going to defend Anhyfix here. I take your point Chris and you're right - to a point.
Anhyfix doen't work quite like cement based adhesives.
The first time I used it was on a floor which was to take 30 grands worth of tiles. So I wanted everything right. In my mind, and as far as common sense told me - it was a good idea to fix the Ditra with a gypsum-based adhesive. Schluter said no, but only because they hadn't tested it.
I used it and was shocked at how easily it lifted - even after 48hrs.
Honestly though; after a few days or more you will not get it up. The bond strength is very gradual, but ultimately very strong. I know this because on the same job I had to lift 9 tiles due to a set-out error (not mine) two weeks later.

I trust it, and I'm using it regularly to fix my Ditra to anhydrite floors.

 

[Dumbo]

I'm going to defend Anhyfix here. I take your point Chris and you're right - to a point.
Anhyfix doen't work quite like cement based adhesives.
The first time I used it was on a floor which was to take 30 grands worth of tiles. So I wanted everything right. In my mind, and as far as common sense told me - it was a good idea to fix the Ditra with a gypsum-based adhesive. Schluter said no, but only because they hadn't tested it.
I used it and was shocked at how easily it lifted - even after 48hrs.
Honestly though; after a few days or more you will not get it up. The bond strength is very gradual, but ultimately very strong. I know this because on the same job I had to lift 9 tiles due to a set-out error (not mine) two weeks later.

I trust it, and I'm using it regularly to fix my Ditra to anhydrite floors.

As I said earlier I don't fit matting and tile the same day as If you have to lift a tile the matting comes up . So if you were to do things like I like to would you recommend fitting the matting then leaving it for 2 clear days before tiling to prevent mat lift if you have to reset tile . Also does anybody know if tilemasters own matting suffers this same problem .

 

[One Day]

As I said earlier I don't fit matting and tile the same day as If you have to lift a tile the matting comes up . So if you were to do things like I like to would you recommend fitting the matting then leaving it for 2 clear days before tiling to prevent mat lift if you have to reset tile . Also does anybody know if tilemasters own matting suffers this same problem .

Agreen is a pain if you need to lift a tile. Ideal world, yes you could wait a few days.
If an anhydrite floor is done properly though it will be so flat that you won't need to lift any tiles!
I've never used tm membrane with anhyfix so I can't comment...

 

[Dumbo]

Agreen is a pain if you need to lift a tile. Ideal world, yes you could wait a few days.
If an anhydrite floor is done properly though it will be so flat that you won't need to lift any tiles!
I've never used tm membrane with anhyfix so I can't comment...

When you're as bad with a trowel as me there aren't many that don't need lifting .

 

[Flintstone]

Every anhydrite I've seen has been pretty much perfectly flat. There shouldn't be a need to lift tiles but sometimes tiling defies logic!

 

[Dumbo]

As you just said pretty much perfectly . As you know large format in particular require more than that. Some companies don't set their levels they just go in with their tripods set from the last job and do the same thickness over the whole over site no matter how bad that is . By the nature of the material that improves the contours as it is a flowing material but much like levelling compound it won't do it on its own

 

[LM]

In the end of day ditra is just a plastic.We try to avoid ditra and use Bal matting where is possible, lay down with Ardex 200.View attachment 91760

To me this makes more sense so I asked BAL about it a while back and they said that they hadn't tested it but that's not to say it wouldn't work. They said that they'd only recommend sticking it down with one of their own cemititious adhesives purely from a sales perspective!

 

[Time's Ran Out]

Surely your leaving yourselves open to guarantee issues if you don't use one suppliers products.

 

[Dumbo]

Surely your leaving yourselves open to guarantee issues if you don't use one suppliers products.

I never rely on manufacturers guarantees .

 

[Flintstone]

Me neither, I'm sure they would there best to blame something else

 

[Blunt Tool]

I've spoken to Bal technical a while back when their mat first came out. Guarantee only comes into play if it's their recommended way to check and prepare sub floor, all materials must be their recommended ones. You must install as they say and must be able to provide proof! Also I was told you must lay mat with their adhesive and you must start tiling straight away so that adhesive under mat and on mat plus tile all dry at the same time like a sandwich. Was told never to stick down mat and leave till next day, only to lay what I can cover in tiles!

 

[Time's Ran Out]

I never rely on manufacturers guarantees .

Me neither, I'm sure they would there best to blame something else

Just for adhesive or for everything?
TV, fridge, car ... because I'am sure the customer does. If you've shown a method statement and kept to it, then you've covered your back.

 

[Mark@Tilemaster]

Hi everyone. I have only just seen this thread so my apologies for the delay in replying. Firstly, I would just like to say that Anhyfix has been around for several years, in that time we have installed hundreds of m2 worth of tiles successfully onto anhydrite screeds, many of them installing an uncoupling membrane, Ditra Matting, Dural CI++, Tilemaster Anti-Fracture Mat and several other systems.

Tilemaster Anhyfix does get a gradual bond to the underside of any uncoupling membrane, equally if the same test was done with a cement based adhesive, a similar thing would be seen. The bond gets stronger as time develops, and as Mark at Imperial has mentioned, try pulling the mat up after 48 hours and the results will be much different. In testing we have done here, we have applied Ditra Matting, Dural CI++ Matting and Tilemaster Anti-Fracture Matting, with C2, S1 and Anhyfix adhesives, we were extremely surprised to learn that the best bond strength we got was from Anhyfix across the board, with all three mattings that were tested.

We know that certain products are only guaranteed with a C2 or cement based tile adhesive, however for us here at Tilemaster, we know that when installing onto anhydrite/gypsum based screeds, a gypsum based tile adhesives delivers a more satisfactory result, both that the products are 100% compatible but also that we are able to deal with slightly higher moisture content that may remain within the screed.

If the manufacturer of the uncoupling membrane will not guarantee their product with Tilemaster Anhyfix, then providing the screed has been prepared correctly, Tilemaster Adhesives will offer the guarantee.

 

[Chris Gibbs]

I've decided I must of had a bad bag or so of anhyfix.., tried it again from a different pile today and it was lovely, smooth, creamy and spread like a dream, pulled back the ditra and bingo... TOTAL COVERAGE!
They have batch numbers on the bags. Does anyone know how to decipher these please?

 

[Dumbo]

Just for adhesive or for everything?
TV, fridge, car ... because I'am sure the customer does. If you've shown a method statement and kept to it, then you've covered your back.

Just for adhesive and grouts. I had a job where the grout dried greyish in colour it was supposed to be limestone . I got some more of the grout mixed it up in small pots , flexible and standard they both dried a different colour to the grout in the floor and even to each other (understandable as one was flexible ) but bal said they were all in the colour parameters if I still had the pictures I would post them . So the upshot was I had to regroup the floor of my own back to keep customer happy ( I wouldn't of been happy if I was them ) with a little help from the retailer. So no I don't rely on guarantee .

 

[Chris Gibbs]

Hi everyone. I have only just seen this thread so my apologies for the delay in replying. Firstly, I would just like to say that Anhyfix has been around for several years, in that time we have installed hundreds of m2 worth of tiles successfully onto anhydrite screeds, many of them installing an uncoupling membrane, Ditra Matting, Dural CI++, Tilemaster Anti-Fracture Mat and several other systems.

Tilemaster Anhyfix does get a gradual bond to the underside of any uncoupling membrane, equally if the same test was done with a cement based adhesive, a similar thing would be seen. The bond gets stronger as time develops, and as Mark at Imperial has mentioned, try pulling the mat up after 48 hours and the results will be much different. In testing we have done here, we have applied Ditra Matting, Dural CI++ Matting and Tilemaster Anti-Fracture Matting, with C2, S1 and Anhyfix adhesives, we were extremely surprised to learn that the best bond strength we got was from Anhyfix across the board, with all three mattings that were tested.

We know that certain products are only guaranteed with a C2 or cement based tile adhesive, however for us here at Tilemaster, we know that when installing onto anhydrite/gypsum based screeds, a gypsum based tile adhesives delivers a more satisfactory result, both that the products are 100% compatible but also that we are able to deal with slightly higher moisture content that may remain within the screed.

If the manufacturer of the uncoupling membrane will not guarantee their product with Tilemaster Anhyfix, then providing the screed has been prepared correctly, Tilemaster Adhesives will offer the guarantee.

That's very kind of you to respond, and giving the fitter peace of mind. We all care about the work we do and it's good to know we have the backing from the manufacturer too.
Thank you.