Warm flat dormer roof construction

[TonyS82]

Morning all,
I am in the process of having a dormer loft conversion completed. the builders have built the frame and started to do the flat roof. As far as i can tell they have layed the pir insulation directly over the joists, then its been boarded with osb and then the epdm.
Looking online the construction methods vary but most mention a vapour control layer.
It seems im missing one.
What are my options please?
Thanks
Tony

 

[Notch7]

VCL should be on warm side - directly under insulation is ideal.

If you aren't having downlighters then foil backed plasterboard is probably fine.

Or foil tape around all joists to join up the foil on the insulation boards.

 

[TonyS82]

VCL should be on warm side - directly under insulation is ideal.

If you aren't having downlighters then foil backed plasterboard is probably fine.

Or foil tape around all joists to join up the foil on the insulation boards.

Thank you Notch. It's good to know these things before asking the builders.