Weather Vanes

[Vagus]

Also considering getting a weather vane to put on the apex of the garage roof and wondering how difficult it might be to fix. Anyone got one?

[davebro3]

why? don't you know which way the wind blows? 

[Buenchico]

This manufacturer offers different brackets for different locations.  It looks to me as the actual installation shouldn't present any real difficulties.  (The brackets are much the same as those used with TV aerials):
https://www.weathervanes-direct.co.uk/mounting-brackets.asp

[Vagus]

Yes Chris, having done some research now, it seems as you say, and as OH is pretty useful with some ladders and a drill, we (I) just need to choose an appropriate one so he can put it up.