Tolerance -> Leveling Screed

Hello, due to a very current issue: I have often read something in the forum on this topic, but unfortunately cannot find anything concrete through the search right now. How "uneven" is cement screed normally allowed to be to be accepted by us. The tiler (commissioned by us) has already indicated: leveling compound will be necessary, also due to the large-format 1.20m tiles. With a 3m straightedge I measure "up to" 5...6mm height difference. With a shorter straightedge (e.g. 2m) correspondingly less, it’s only about a few small bumps. It also has nothing to do with drying, the screed has been in place for 2 weeks and the bumps were there from the beginning and have neither improved nor worsened.

Google something about DIN 18202.

Perfect, thank you very much!

We will measure again exactly, but I fear the screed will probably meet the DIN...

Screed must be made by quite clumsy people to not meet the DIN standards. Leveling compound doesn't cost a fortune, it was also used in almost all rooms in our place.