I have 2 MK04 Comfort windows to be installed recessed on a slate roof, batten. EKNN 4021E - Recessed installation, and a double flashing kit.

However, I can't seem to get it to work in my batten roof. I asked Velux but they told me to add flaps! That's not possible.

Did anyone else have this problem with installing this window in a batten roof?

Attached is an example of my roof type.

Thank you very much.