Sand and Cement Grouting- Flexible Additive?

[tilerman]

Hi, i am tiling a large kitchen floor that has underfloor heating with a natural slate tile. I am going to be using a silver sand/cement mix for the grout. Using conventional grout for floors with underfloor heating i always add an additive (or use a single part with additive in mix) Is there a flexible addy that i can add to a sand and cement mix? If so, which brand/type? Many thanks in advance.

Dennis

 

[r896neo]

lime? To be honest mortar additives are really to improve workability or waterproofing etc and not really designed for flexibility.

In reality for tiling mortar you can use thin-set which as far as i know has latex in it but i think you buy it as a product rather than simply add to normal mortar.

That said a dose of SBR may have exactly the same effect.