Question : sequence of internal lining

[Yvonne]

Hello

SIPS build. 

1. Plan detail : external cladding/strapping/barrier/OSB solid insulation OSB/strapping/void/25mm PIR foil both sides/12.5 plasterboard
2. Looking on kingspan website as below it has the 25mm foil insulation next to OSB then strapping/plasterboard 
3. Neither setup have an internal,vapour barrier 
4. are both correct 1.& 2. do o need a vapour barrier?

 

🤯🤯🤯

thanks in advance 

[Redbeard]

I imagine they will say that the TW55 is the VCL, which is true as long as all joints and perimeters are taped to within an inch of their lives and nobody pokes a screwdriver or a fingernail through the foil.