Dave, Dave, Dave, Dave, no, no, no, no, no!
I've been caught out on pitched roofs before and its scary; don't do it; fella. If you can't get to the window without being 'spiderman', don't do them, otherwise you'll end up like Freddy Flintstone.
Besides which, those thin slates are about as thick as beermats. I'm sure I'd crack a few if I tried that.
