Hello,
I'm currently building an extension and loft conversion.
The loft will form "part" of a bedroom, and i'm keen to make it as efficient as can be.
I deliberately used 7 inch rafters on the new part of the vaulted ceiling, in order to use 4" of PIR and a suitable air gap.
However the old parts of the house have just 3" rafters.
I cannot afford to lose any more headroom. I've just replaced the roof so don't want to go upwards. We don't have to meet building regs as far as I know in this part, which brings me to my question.
Do I use 70mm of plain old/kingspan/cerotex etc etc. Leaving very little/no air gap the breathable membrane. Sealed around the joints with expanding foam.
Or do I use some form of "super quilt" (I don't buy into how well they work) But in this application could it work, if sealed, air gap etc etc.
Or is there some other way?#
Thanks for any input.
I'm currently building an extension and loft conversion.
The loft will form "part" of a bedroom, and i'm keen to make it as efficient as can be.
I deliberately used 7 inch rafters on the new part of the vaulted ceiling, in order to use 4" of PIR and a suitable air gap.
However the old parts of the house have just 3" rafters.
I cannot afford to lose any more headroom. I've just replaced the roof so don't want to go upwards. We don't have to meet building regs as far as I know in this part, which brings me to my question.
Do I use 70mm of plain old/kingspan/cerotex etc etc. Leaving very little/no air gap the breathable membrane. Sealed around the joints with expanding foam.
Or do I use some form of "super quilt" (I don't buy into how well they work) But in this application could it work, if sealed, air gap etc etc.
Or is there some other way?#
Thanks for any input.
