ᐅ Tolerance → Floor screed flatness

Hello, due to a very recent issue: I have often read about this topic in the forum, but unfortunately cannot find anything specific through the search right now. How uneven is cement screed usually allowed to be in order for us to accept it? The tile installer (appointed by us) has already suggested that leveling compound will be necessary, partly because of the large-format 1.20 m (4 feet) tiles. When measuring with a 3 m (10 feet) straightedge, I see differences in height of up to 5 to 6 mm (0.2 to 0.24 inches). With a shorter straightedge (e.g. 2 m (6.5 feet)), the differences are correspondingly smaller; it’s only a matter of a few minor bumps. This has nothing to do with drying—the screed has been in place for two weeks, and the bumps were there from the beginning and have neither improved nor worsened.

Just search for DIN 18202.

Perfect, thanks a lot!

We will measure again precisely, but I’m afraid the screed will probably meet the DIN standard...

Screed would have to be installed quite carelessly to fail to meet the standard. Leveling compound isn’t expensive and was used in almost all of our rooms as well.