1. Don’t protect your floor screed
2. Let the water in
These pictures tell a 1000 words. Water ingress is a guaranteed way to ruin your floor screed.
See these:
3. And oh, while we are here, if you really want to make friends on site, just use your boots. Don’t mind us, walk on the screed. My kids love to do this on the beach. Why do it on the screed? Cmon guys this is not rocket science.