Slc over ditra

[Giovanni]

I've always used Slc then ditra on top but I'm on a job and another tiler does it the other way, ditra and then Slc. What's the drawbacks doing it his way as I'd prefer to do it that way as ditra is a pain to tile onto.
Surely it's ok as you can Slc over ditra heat.

 

[White Room]

I've heard of it but not the prefered way I do it, have also heard of spf being used to fill ditra.

 

[Stef]

I posted this on a FB forum a while back.
I had a flyer through the door from Ardex & it showed slc getting poured on top of Ditra 25, I think a quick phone call to Schluter would be needed but the Ditra should be on top below the tiles.

 

[hmtiling]

SLC on top loses the mechanical bond between the adhesive and ditra. The bumf I've read from shluter says all prep first.

 

[J Sid]

made that call "don't do it" was the answer

will take the allowable build up between top of ditra and underside of tile to big and the uncoupling properties of the matting will not work properly

 

[Stef]

I've commented on posts on tile geeks about pre filling Ditra & told the Americans that it's a no no over here but the majority of them do it in the states.
I've even explained how Ditra works but they state because addy will stick to addy they don't see the problem.

 

[J Sid]

Ditra only works if the adhesive DOESN'T stick to the plastic surface, that's why highly modified adhesive is a no no

 

[Old Mod]

From memory of Schluter course, preffered method is definitely prep first, with Ditra always being as close to finish floor as possible. i.e. Top layer.

 

[Giovanni]

I've asked the question before to a schluter rep and said how come they recommend to Slc over ditra heat and not normal ditra and he couldn't give me a proper answer , he just faffed.

 

[Old Mod]

I've asked the question before to a schluter rep and said how come they recommend to Slc over ditra heat and not normal ditra and he couldn't give me a proper answer , he just faffed.

I wouldn't be so sure you are correct in that statement.

 

[J Sid]

well found, was just looking as it sounded wrong

 

[Giovanni]

Interesting that 3 fall. The rep told me I could use Slc over ditra heat to save on adhesive. Cheers for the info tho.

 

[One Day]

How about this then?: In some places they comb the floor with 12mm notch of runny adhesive then roller the Ditra to the adhesive - UPSIDE DOWN.
Why?
Saves time filling the holes.

Look - if it works, it works. Maybe not in the labs, but in the real world.
So if it works - do it. If it doesn't - don't.
If you're unsure - ask.
But take it from me - you're far better off working it out for yourself.

 

[Time's Ran Out]

Yeah - I'am sure they will stand by any guarantee if you do that!

 

[One Day]

Yeah - I'am sure they will stand by any guarantee if you do that!

Maybe you miss the point? it's about finding what works for you. If the upside down malarky works, then i can see the sense in it. Personally i wouldn't risk it. But i do, on larger areas flood my ditra with slc. I've discussed it with different people at schluter before and there is a risk of reducing performance, but not if the bond is strong between your slc dovetails and the adhesive bed.
As i say, not by the book, but it works.
Manufacturer's will always minimise risk involved in their products by simplifying useage as much as possible. There will always be idiots using things wrong, but there will always be 'idiots?! ' using them differently.

 

[One Day]

As for guarantees, i used anhyfix under 300sqm of ditra. No guarantee because i did that. Why did i do it then? Common sense says that I've minimised my risk. Schluter haven't officially tested the product so they won't guarantee it. Mark at TM has and he has faith in it, as do i.

 

[Stef]

As for guarantees, i used anhyfix under 300sqm of ditra. No guarantee because i did that. Why did i do it then? Common sense says that I've minimised my risk. Schluter haven't officially tested the product so they won't guarantee it. Mark at TM has and he has faith in it, as do i.

Anhyfix will stick to anything. I've a few bags left over from jobs & trying to use it up on wall tiling.
I've no more gypsum screeds coming up & don't want to have it too long before it gets used.

 

[Time's Ran Out]

Impish -
I've 'missed the point' how do you reckon that?
Your advocating on a forum to use a product incorrectly and then saying you wouldn't risk it after that method was questioned.
It's the type of advice that may cause a problem/failure and leaving those seeking professional help without any manufacturers guarantee.
Not sure where you stand with your 'idiots' comment.

 

[MW Smith Ceramics]

I've spoken with Schluter and any gypsum based adhesive is not recommended to lay ditra so if you do then Schluter won't back you up if you have a failure.......

 

[One Day]

You know what? I'm going to shut up.

 

[Old Mod]

Interesting that 3 fall. The rep told me I could use Slc over ditra heat to save on adhesive. Cheers for the info tho.

Now see, that's not what you said in your post was it! Haha
You said

how come they recommend to Slc over ditra heat and not normal ditra and he couldn't give me a proper answer , he just faffed.

Which is not actually the same thing is it! Haha
Your second post makes much more sense, good to know too!

 

[Aston]

How about this then?: In some places they comb the floor with 12mm notch of runny adhesive then roller the Ditra to the adhesive - UPSIDE DOWN.
Why?
Saves time filling the holes.

Look - if it works, it works. Maybe not in the labs, but in the real world.
So if it works - do it. If it doesn't - don't.
If you're unsure - ask.
But take it from me - you're far better off working it out for yourself.

I get what you are saying but when you say ''if it works, it works'', and in the ''real world'' etc BUT How long does it work? wheres the testing and the long term proof..

Trust me, Ive been in the construction industry since 1985 and if I had to take the word of a science dept or a guy with a hunch, then i'm going with the science dept..why?? because they prove what they claim works.

BUT I hear what you are saying and I get respect your view.

 

[One Day]

I get what you are saying but when you say ''if it works, it works'', and in the ''real world'' etc BUT How long does it work? wheres the testing and the long term proof..

Trust me, Ive been in the construction industry since 1985 and if I had to take the word of a science dept or a guy with a hunch, then i'm going with the science dept..why?? because they prove what they claim works.

BUT I hear what you are saying and I get respect your view.

Then I thank you
As a profession we really need to start getting away from being "babied" and spoon fed all our info from manufacturers. For too long they've held all the cards. They should be really be working with us and for us, instead of trying to simply milk us all for profit.

Times - they are a changin'... (or will be soon I hope)

 

[Aston]

unfortunately that's the cut throat world of business and profit and it ain't going to change.

they report back any minuscule changes in temperature, expansion, grip, water resistance and whatever else they want to use as a reason to increase prices or launch a 'new improved product'. they try to brain wash us through marketing, 'freebies for trials' and hearsay through regurgitation of gullible forum members BUT if you know different and you can prove it, then I say use it and keep it to yourself and your apprentice because if you say it on here, or there for that matter, not every body will buy into your experience because.....we are just ordinary tradesman, with no clout, no influence and no importance...........cruel but true.