Where to put insulation

[Mr Coeur de Lion]

In the process of converting an old timber outhouse into an office. We are putting insulation in (the silver stuff with many layers approx 3 cm thick).

There will be air gaps between the inside of the timber to where the BA13 starts of perhaps 10-15cm or even more in some places. Where is the best place to fix the insulation? To the timber or to the BA13, or doesn't it really matter? I have already lined the shed with plastic sheeting for extra waterproofing.

Many thanks.

[tj]

You should have an airgap on BOTH sides of the insulation of a minimum of 2cm.

We normally fix the insulation to the chevrons, then batten horizontally with 2 x 1, and fix plasterboard to finish. 

[Mr Coeur de Lion]

I think I probably have that. Certainly one side of the structure is very irregular, and the insulation I have put up there is certainly not fixed to either wall in most places. So that's good.

Thanks for that, and I will bear that in mind for the rest of the project.