OSB board

[Trackman]

Hi there, looking for some advice please.

I am insulating above our 3bay garage in between the rafters with 100mm celotex and I want to panel out the whole roof and end gables with OSB board.

I was looking at using 9mm thick OSB as it’s non structural area, what does everyone think? Is 9mm ok?

thanks in anticipation 

[Iceverge]

Is it for hanging shelves etc from? 9mm is a bit thin IMO. 

 

You might save yourself a lot of money and Hassle using batt insulation between the studs than cutting PIR too