Garage conversion help needed, insulating walls

[garydc]

We're currently doing a garage conversion, bit of a case of some DIY and tradesmans help. Its 103mm single skin walls, no cavity, etc.

We've entirely blackjacked the walls and floor, 3 coats, laid a 1200 gauge DPM to 30cm, now about to start building a timber frame stud wall with Celotex.....have bought these materials....3"x2" treated timber, 50mm GA4050 Celotex and was planning on building a stud wall with Celotex cut into the 600mm gaps.

However, I'm now being told that leaving a 1" void between Celotex and plasterboard is not sufficient, and that it must be 2".

Any ideas, as I read conflicting stories on different sites, some say 1" and others 2".

 

[Jameswren]

What's the issue leaving the extra inch?

 

[theoldun]

We're currently doing a garage conversion, bit of a case of some DIY and tradesmans help. Its 103mm single skin walls, no cavity, etc.

However, I'm now being told that leaving a 1" void between Celotex and plasterboard is not sufficient, and that it must be 2".

Any ideas, as I read conflicting stories on different sites, some say 1" and others 2".

Remember this post below my friend???
For us, once bitten, twice shy.
Suggest you continue learning about about interstitial cavities, condensation and trying to cut corners
oldun

Thanks all, I am cracking on. No way I'm going back now or making the room any smaller. Need to get done, so I can move onto our extension.

"show them and tell them its 75mm".....i like the sound of this

B