Calcium sulphate screed preperation

[Ajax123]

Yes the customer went with the builders advice in this floor choice , saying that it was a better product for ufh and shrinkage etc !

It is.

 

[area tiling]

My customer is just of the phone to me , saying that the screening company that laid their floor said that the floor doesn't need sanding or grinding as theirs no lataience residue ! They informed them that it was a hemihydrate screed , and that it only would require to coats of acrylic primer! Does this seem correct?

 

[Sean SML Tiling]

Get them to out it in Writing to cover your butt

 

[Stef]

My customer is just of the phone to me , saying that the screening company that laid their floor said that the floor doesn't need sanding or grinding as theirs no lataience residue ! They informed them that it was a hemihydrate screed , and that it only would require to coats of acrylic primer! Does this seem correct?

As far as I'm aware you need to remove laitance from them all, even the low laitance screeds.
Wait till Alan's (Ajax) back on, he's your man.

 

[Ajax123]

My customer is just of the phone to me , saying that the screening company that laid their floor said that the floor doesn't need sanding or grinding as theirs no lataience residue ! They informed them that it was a hemihydrate screed , and that it only would require to coats of acrylic primer! Does this seem correct?

No. In fact all screeds and concretes should be sanded prior to the application of bonded floor coverings. This included sand cement screeds, power float concretes, anhydrite and he I hydrate screeds. It is part of the guidance of the manufacturers and the floor trade associations. It is part of the guidance from most adhesive and primer companies.

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Get them to out it in Writing to cover your butt

What difference would that make if the flor fails and you haven't prepped right it's your fault....

 

[area tiling]

Thanks Alan, for all your help its, guys like you on this forum that keep us right! But I do find this all very confusing one company say one thing the other company say something different , and am pretty sure that no one sand's down a sand cement screed before tiling, they and I , included only prime !