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 ?