Advise welcome....loose tiles..

[Joe90]

We laid some rectified porcelain tiles, with wet ufh, on anhdrite screed..
Floor was dry before tiling,
Had been through a warm up and down cycle,
lattice (scum) on floor was sanded off,
Dust was removed to leave a clean dry surface.
Benfer soloflex adhesive was used, no need for primer according to the technical sheet supplied by the tile shop.
3mm spacers with plastic lifters were used.
Flexible grout
Floor was left for two and half weeks to dry naturally before ufh was turned back on, then left on low for two weeks before it was turned up to heat the room as required.

Now i have a few tiles that have Come loose... Haven't lifted one yet to determine if it's tile to adhesive or adhesive to floor....
Any thoughts forum members..????

 

[CJ]

Does the tech sheet you read, have any mention to anhydrate screeds/priming??



Scrap that......I just looked

 

[Old Mod]

You need to lift a tile, simple.
You can’t guess, there’s many reasons a floor can fail.

 

[Simon Dale]

Whenever I do one I get my friend to go over it with Diamond grinder ? Tried black pads once didn't get enough off !

 

[Old Mod]

Whenever I do one I get my friend to go over it with Diamond grinder ? Tried black pads once didn't get enough off !

Agreed Simon, did a failed anhydride last year which had been sanded, client confirmed the process had been done.
Thing was it was poorly done, large format tile, it had lasted 9 months.
If I could have removed the adhesive from the tiles, I could have re used them elsewhere, they virtually all came up in one piece. Shame.

 

[Simon Dale]

I cant really see the point of them ? I use a screeder who is nearly spot on. They say it is good cos its level ! Never had one level Lol

 

[Old Mod]

I cant really see the point of them ? I use a screeder who is nearly spot on. They say it is good cos its level ! Never had one level Lol

To be fair, the one above was like a billiard table, perfectly flat and level, an actual joy to fix to.

 

[Simon Dale]

Is 3 coats of primer still the Norm ?

 

[Old Mod]

That’s the way I approached Si, yeah.
I used a ready mixed primer 50/50, 75/25, and neat.
(Ready mixed neat, so to speak )

 

[Joe90]

Thanks for the interest guys......
I when I've lifted one I will let you know... Hopefully get that done tomorrow......
The floor was skimmed over with a diamond blade sander... Not a sandpaper type material.... So it removed quite a lot of material...... This was done by the screed company about 2 months after it was laid...

 

[macten]

Sure it should be done 4-6 days after application.

 

[Dumbo]

My bet is although it says doesn't need priming i reckon a coat of primer wouldn't of hurt because after cleaning up prior to tiling i expect there was still some dust present that the primer would of put down . There us a difference between doesnt need priming and whatever you do in any way shape or form do not prime .
Also did you back butter the tiles . Good practice but another thing it says you don't need to do .

 

[WetSaw]

That's quite a long time to wait to remove the laitence so it would have taken quite a bit to remove it. I would also have primed it, regardless of the adhesive instructions. I can't see how any adhesive is going to be as efficient with 2 surfaces of such differing absorption rates.

 

[Joe90]

Because of the primer issue, which is how I would normally seal a floor I was pretty particular about dust residue on the surface.. There was defiantly no dust or loose particles on the surface before it was tiled.... The tech sheet says no primer, the shop where it was purchased from said the same when I questioned it... As far as I know Benfer don't have any uk representatives to talk to... As told by said shop....!!
Tiles were back buttered, no dust or residue on the back...
If I'd have sealed the floor , as I would think should be the case and we'd have had an issue , then they would say we shouldn't have done it...!!!

 

[Italy]

I've never used this brand. But I looked at the technical sheet of Soloflex and says: anhdrite screed. Apply Primer.
http://www.infobuild.it/wp-content/uploads/SOLOFLEX-S1-IT.pdf
sorry, I do not find it in English, it is on page 2