When Do You Uncouple?

[MW Smith Ceramics]

Hi Stef,

Just reading through these posts.......so I was just having a chat with one of the bal technical advisors last week and I just wanted to know there method of fixing onto calcium sulphate screeds as every tile fixer on here seems to use tilemaster anhyfix but just have a read through this PDF and let me know your thoughts......this is coming from the largest and longest serving manufacturers of tile adhesives in the country and a gypsum based adhesive isn't even in the installation process.......apparently this is British standards..........personally I fix bal rapid mat down with a gypsum based adhesive then a flexible cement based adhesive onto the mat.........every screeding contractor I seem to come across states that we must use a gypsum based adhesive.........why is this not British standards is what I'd like to know.........any feedback on this would be interesting......thanks

Mark

 

[MW Smith Ceramics]

Sorry, here is the PDF from building adhesives ltd

 

[MW Smith Ceramics]

Not sure if I've linked this PDF correctly to the site......let me know if not & I'll try again ......Cheers

 

[Stef]

It is not in British standards because British standards haven't quite caught up with the gypsum based adhesives.
These new screeds (15+yrs) are just being introduced into this country & they haven't quite caught up yet.
I take my info from Alan (Ajax) on here & what he says is gospel to me as he was one of the 1st to bring these screeds into the UK.
That's good enough for me..

 

[Stef]

I've phoned Mapei, Weber & Bal about these screeds & they have all told me that one coat of primer & then any cement based addy will suffice.
In my experience this is not good enough as you have to create a barrier between cement & gypsum & that entails 4/5 coats of primer..

 

[hmtiling]

I've phoned Mapei, Weber & Bal about these screeds & they have all told me that one coat of primer & then any cement based addy will suffice.
In my experience this is not good enough as you have to create a barrier between cement & gypsum & that entails 4/5 coats of primer..

Weber have done gypsum based adhesive in mainland Europe for a good few years. Very strange that they give conflicting advice in the UK to the rest of Europe.