yes.. behind the pergola.. twice heavy rain within a week. But I only sowed it in June. I do it in stages, otherwise I can't water it.
The lawn was washed away, and now it grows everywhere it shouldn't.. even on weed fabric without soil :-/
Edit: I also have to be honest.. I would no longer roll at the end. The soil then absorbs water much worse. It is said that lawn is a light-bodied seed and should not be worked in, but this worked perfectly: rolling, applying fertilizer and lawn seed, and lightly working it in with a rake. The surface is rough and the water soaks in immediately. That worked perfectly. I rolled the second section at the end, and with every little rain there are puddles!