Which adhesive to the ditra mat on the anhydrite screed with water UFH

[Bartosz]

Hi. I have about 55 sqm floor, anhydrite screed laid about 5 years ago with water UFH. Because my house is old, build 1902 on side of the hill and on the clay, I have few crack on floor. One of the first shop where I was looking for tiles, wood effect which I want, was Topptiles. Because crack they offer me Durabase and, because UFH, own adhesive S2, so base on this suggestion I start my research on this forum, and I replaced Toptiles Adhesive for Tilemaster Ultimate Flexible Rapi S2 and mat for Ditra. But before maked final order I was look again what U use to adhere Ditra mat to screed as mine and I could not find exactly the same situation but few other application suggests S2 adhesive could be wrong to use in this combination so what is Your suggestion what type and brand adhesive I should use ?

 

[Spare Tool]

Sand laitance, prime, TM Anhyfix for the ci mat, and standard setaflex S1 to fix tiles..

 

[Ajax123]

Ditto Andy's advice

 

[J Sid]

for me
Ditra stuck down with ARDEX af200 onto anhydrite after it has been sanded
a highly modified adhesive can't be used to fix tiles to Ditra as adhesive is locked to cavities in mat and not stuck to mat.

 

[Just Rizzle]

ether of the above the ardex is basically a ht vinyl addy both are suitable
if the floor has been down for five years what have u had on it carpets or wood

 

[Bartosz]

It's long story... But after I sanded and primed I left not covered because I lived on the first floor when do work on ground floor. But floor heating work and I have another question about that. I believe I need switch heating off during tiling work but how to switch on is it any procedure like with screed drying or is not necessary.

 

[Ajax123]

Switch it off for 3 days prior to sticking stuff down then recommission 28 days after filing innthecsaje as you did to dry the screed ie on low for 3 days then increase gradually

 

[Bartosz]

Thanks for all advice. One more please. Anhyfix coverage - description 20kg will cover 5 – 6m² at 3mm thin bed application where Tilemaster Anhyfix Adhesive - https://www.tilersforums.com/threads/tilemaster-anhyfix-adhesive.69195/page-3, Peter say is 16 m at 4mm. I want buy exactly quantity as possible because I will buy online, price.

 

[Spare Tool]

Your confusing bed depth with trowel notch size..
When fixing ditra or ci mat use a 6mm notched trowel and out of a 20kg bag i would expect to get 7-8sqm so 8 bags would be sufficient for your 55 metres.. Bear in mind its a rapid setting adhesive so don't mix up too much at a time or you'll be throwing away more than you actually use.

 

[Time's Ran Out]

Don’t forget to roll the mat into the adhesive !