I was wondering if I can add the R values of an air gap and celotex above like in this:
[code:1]
~40cm between joists
10cm | celotex |
5cm | air gap |
plasterboard -----------------
[/code:1]
So if I have an unvented air gap of 5cm at the bottom, the R value is 0.05m/0.024 (thermal conductivity of air) = 2.1
10 cm of Celotex should have R value of ~ 4.5, so if I add these two I get 6.6, which satisfies building regulations (6.1 if I am not mistaken).
I think this is the only way I can board my loft without adding more than one layer of anything above the joists.
[code:1]
~40cm between joists
10cm | celotex |
5cm | air gap |
plasterboard -----------------
[/code:1]
So if I have an unvented air gap of 5cm at the bottom, the R value is 0.05m/0.024 (thermal conductivity of air) = 2.1
10 cm of Celotex should have R value of ~ 4.5, so if I add these two I get 6.6, which satisfies building regulations (6.1 if I am not mistaken).
I think this is the only way I can board my loft without adding more than one layer of anything above the joists.
