Holding warm roof together

[Yarners]

i am about to put a warm flat roof on a detached home office I am building. I need a bit of advice on how it all holds together.

On the wall plates I fix the joists. Then I nail the deck. That's easy.

On top of the deck goes insulation boards and OSB3 on top so I can finish with fibreglass, which I have to use as I have got all the stuff. My question is how do I hold these in place? I see a lot of diagrams showing this type of construction but at no point is it clear how the top doesn't just blow off.

Thanks

 

[freddiemercurystwin]

How about ................................ screws? eg http://www.fixfast.com/ProductGrp/SIP_fastener_for_steel_and_timber_decks

 

[Yarners]

Thanks.

I know it's really obvious to you chaps but I was concerned about screwing into those insulation boards.