Liquid screed, laitence and tile disaster

[Parton42]

We've had a disaster (and I cried a lot) and now need help please.

We laid porcelain tiles with Mapei (Flexpro?) adhesive over a liquid screed floor which is white which still had laitence.

Wise after the event, we now know that tiles do not like that and they all started to come up. There was a whitish powder on the bottom of them and they literally just lifted off the floor with one finger. We couldn't even clean the Mapei off the back of the tiles to reuse them.

We have now totally sanded the screed floor with a diamond tipped grinder so it is ready to try again. The floor was laid in Feb and is totally dry and it also has UFH which has been commissioned.

We are planning to use Flexmaster Multi Purpose Flexible Additive and Primer on the floor with Anhyfix adhesive to lay the porcelain tiles.

If anyone has any advice or suggestions it would be very much appreciated as we cannot bear anything else going wrong.

Many thanks

 

[AliGage]

Personally I have never experienced an Anhydrate floor before.

What I do know,

Check it's dry and free from moisture.
Remove/sand latience

Adhesive choice is correct.
I would be inclined to use a decoupled over your UFH though.

I'm sure someone will jump on with a more experienced and thorough response for you soon though.

 

[Ajax123]

Adhesive choice is INCORRECT. Use a gypsum based adhesive as these are screed compatible. Your mapei choice is not. You also do not mention ifpyou primed the screed but no matter as you will need to prime with an acrylic primer e.g tile master prime plus primer and anhyfix adhesive. Other gypsum systems are available.... Uncoupling is not really necessary for porcelaine but is optional.

 

[Lee@emctiles]

Adhesive choice is INCORRECT.

think what @Ajax123 was stating is the adhesive choice when job went wrong was incorrect, the adhesive mentioned to remedy the job, Anhyfix, is the correct adhesive.

I would use Primelus 3:1 primer then Anhyfix. If porcelain going down, no need for a decoupler.

 

[G Taylor Tiling]

Yes seal the floor, and use correct adhesive Kerakoll ideal is great, and if you do go for anti crack matting then lay this with correct adhesive, then you can use any make rapid etc. on top of the anti crack matting... All will be fine

 

[Dan]

Sounds like it'll be a nice floor when done and well worth it.

Sorry to hear about the tears!

Stick some pictures in the thread when you've done it.

 

[Ajax123]

think what @Ajax123 was stating is the adhesive choice when job went wrong was incorrect, the adhesive mentioned to remedy the job, Anhyfix, is the correct adhesive.

I would use Primelus 3:1 primer then Anhyfix. If porcelain going down, no need for a decoupler.

Sorry my bad.... Misread the op