The bathroom window that I'd like to attach a roller blind to has a
trickle vent opening at the top of the window frame. If I attach the
roller blind to the window frame itself, then I'll have to leave a 1
inch gap at the top.

I'm pretty sure this will look odd so the only other possibility is to
attach the blind mechanism to the inner window recess which will mean
having to drill through tiles.

Before I do this I was wondering if instead of screwing the mechanism
to the vertical walls, I could use some strong adhesive (i.e. No More
Nails glue) instead? The actual mechanisms would have a sirface area of
about 3 square inches.

Any thoughts?

Thanks,
Wayne.