Which internal wall insulation type?

[richo106]

I am studding out some old walls to make them nice and flat and add some insulation (75mm PIR to reach my 0.18 target)

However now I’ve nearly done one wall I am thinking it might be better to use rockwool (omnifit) I have some left over 50mm + 70mm so I can use this to insulate between the studs. The gap from the wall to front of stud is about 130mm.

Is there any issue in me using that or would PIR be better?

 

 

[Temp]

120mm Rockwool is probably going to have similar insulating properties to 75mm PIR but will be easier to fit between studs with fewer gaps. So possibly a better result unless you do a good job of fitting the PIR without gaps.

 

[nod]

Bit late now But if you do anymore the studs are better free standing rather than all that timber fixed to the wall 

rockwool slabs are best for sound insulation But you will have more sound transfer through the timber which ever you decide to use