Ceiling Service Void on Warm Side - Build-Up Advice

[boxrick]

Hello folks!

 

I am building a new roof with my house refurbishment, a high efficiency build and am  working on the ceiling service void, which will be on the warm side of the airtight layer, and I am looking for a bit of guidance on the typical build-up.

 

My builder has a few questions and we are hoping to get this right from the start. 
 

What is the usual way to build up the ceiling void in this situation?

Does it need to be physically separated from the insulation layer by a layer of plasterboard or wood?

Any advice or examples would be really appreciated. Just trying to understand what works, my architect has been thin on details here.

[Redbeard]

In all the jobs I have done or seen with a service void there is usually a VCL immediately behind the battens. Some use 2 battens at 90 degrees so cables can pass up and down as well as side-to-side. Remember that in screwing through (??) the insulation to form a service void you pierce the VCL. Optimists say a hole with a screw in it is not a hole at all. Pessimists gun silicone into the hole and then screw through, giving your screw and airtight (hopefully!) silicone grommet.