do I need a vapour barrier?

[Tom]

Hi all, looking some advice on the question of vapour barriers. Out roof make up (from outside to in) is 

 

150mm composite panel (essentially PIR sandwiched between sheet metal)

200mm rockwool

plasterboard

 

I had planned to tape the internal seams between the composite sheets for airtightness. Do I also need a vapour barrier? 

Many thanks

Tom

 

Edited September 18, 2023 by Tom
typo, thanks markc....

[markc]

You have plasterboard on the outside?

[Tom]

Yep. Moisture resistant. Should have gone for Aquapanel in retrospect