Garage roof. Membrane, battens, slate or OSB too?

[f0rmula]

I'm about to do my garage roof. Looking at my house, I can see that it's just a breathable membrane, with battens and then slate. I worry that if I'm swinging a large piece of timber about in my garage (as you do), if I smack a slate from the underside I'm going to break/dislodge it. Is it completely crazy to do a layer of OSB, breathable membrane on top of that, then battens and slate? It'd just give a more solid feeling to the inside of the garage (along with proving extra bracing).

12mm OSB is cheap enough. Is this a crazy thing to do?

Cheers for any opinions

 

[Alastairreid]

No problems fitting osb but you will need to counter batten the roof before tile battening.