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- 29 Sep 2016
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Hi all,
I'm planning to build a large garden Room and want to do it to a decent spec. Planning to use double glazed pvc windows/ doors and EPDM roofing. For the wall studs I'm probably going to use 4x2 C16. The outside will be glad in 38 mm thick double tongue and groove loglap. When it comes to insulation I am looking to use 50 mm rigid between studs and then the dilemma comes.
I really like the idea of fully wrapping the outside of the building in 25mm kingspan and then cladding over this. I would probably clad onto battens which are inline with the studs, so that the insulation is effectively sandwiched between a timber batten and the stud. I would use some sort of spacer the same thickness as the insulation to keep the battens straight.
I am assuming that when this outer wrap of foil board is in place it will also be a vapor barrier and leaves any breather membrane I choose to include a bit pointless?
This leads me to wonder if I am better off insulating the inside with the kingspan, over the studs with taped seams and then go for a breather membrane such as tyvek on the outside?
I may have kinda answered my own question here but hopefully it gives an indication of my current thoughts. I am also wondering if I would need an external cladding of osb on the outside of the studs.
So in summary:
1) Kingspan on outside or inside?
2) Do I need OSB?
3) Does anybody have any recommendations for the wall construction layers?
4) Does tyvek need and air gap on a particular side?
Any help much appreciated.
I'm planning to build a large garden Room and want to do it to a decent spec. Planning to use double glazed pvc windows/ doors and EPDM roofing. For the wall studs I'm probably going to use 4x2 C16. The outside will be glad in 38 mm thick double tongue and groove loglap. When it comes to insulation I am looking to use 50 mm rigid between studs and then the dilemma comes.
I really like the idea of fully wrapping the outside of the building in 25mm kingspan and then cladding over this. I would probably clad onto battens which are inline with the studs, so that the insulation is effectively sandwiched between a timber batten and the stud. I would use some sort of spacer the same thickness as the insulation to keep the battens straight.
I am assuming that when this outer wrap of foil board is in place it will also be a vapor barrier and leaves any breather membrane I choose to include a bit pointless?
This leads me to wonder if I am better off insulating the inside with the kingspan, over the studs with taped seams and then go for a breather membrane such as tyvek on the outside?
I may have kinda answered my own question here but hopefully it gives an indication of my current thoughts. I am also wondering if I would need an external cladding of osb on the outside of the studs.
So in summary:
1) Kingspan on outside or inside?
2) Do I need OSB?
3) Does anybody have any recommendations for the wall construction layers?
4) Does tyvek need and air gap on a particular side?
Any help much appreciated.