Aaron,
how far up under the bottom tiles does the flashing sheet go?
It should extend up a couple of tiles if its a fairly flat roof.
other than that its lots of ugly silicone or make some cement sheet sutouts to fit and then silicone them in. but having said that i bet there is a product already available for this very job, its just that ive never seen it and im on a roof most days for work.
Cheers Ian![]()