I have a single brick utility that's been battened and then plasterboarded. The problem is there's no insulation in the void between the brick and plasterboard. The easiest way to remedy this would be to pour eps beads in, would this cause damp issues or would sealing the brickwork outside eliminate this.

 

 

 

 

 

The beads would help but you will still get cold and damp crossing the battens and into the PB. Sealing the brickwork would minimise damp coming in but moist  air will still go from inside through the PB and condense on inner face of brickwork causing more damp

That was my thoughts, I'm currently in the process putting new insulation in the loft space and the foil bubble wrap on the rafters. (Plenty of airspace)

It's going to be a Ball ache to redo the walls as there's a toilet cistern and cupboards on the "outerwall"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is External Wall Insulation not an option? If you have access to seal the brickwork, you have access to clad with insulation. Then your internal arrangement will be OK as-is. 

I have but I was trying to find an easier/cheaper option.

 

 

 

 

Not sure this helps but would loose fill/blown wood fibre insulation be any better? That would then give breathability including hygroscopicity, which might help avoid damp? 

https://www.ecologicalbuildingsystems.com/product/thermofibre#technical-details for instance

 

Never used the stuff and not sure if you have to blow it in or can use loose fill but worth looking into??

I think steico also make a similar product

 

 

 

 

 

Just now, larry said:

Not sure this helps but would loose fill/blown wood fibre insulation be any better? That would then give breathability including hygroscopicity, which might help avoid damp? 

https://www.ecologicalbuildingsystems.com/product/thermofibre#technical-details for instance

 

Never used the stuff and not sure if you have to blow it in or can use loose fill but worth looking into??

I think steico also make a similar product

 

 

 

 

 

Another thought, just how deep are those battens? I wonder how much insulation you'll actually be able to get in there in any case. 

 

Another product I came across was diathonite evolution, again not used it but it is also IIRC 0.04 w/mk so comparable to wood fibre/glass fibre etc as a render or plaster, so could go outside and poss may be easier than proper EWI depending on your setup?? 

Best method would will be strip off the plasterboard and battens, megastick and screw (thermally broken)100mm celotex to the complete wall then stick new plasterboard and skim.