Just about to vault a 4m section of roof midway along the bungalow - just one half of the pitched roof. Therefore a section of the purlin needs to come out and two triangular side walls need to be built up in block to support the purlin ends - and then a rear stud wall built up towards the main ridge. Structural plans are all in hand for steels and timbers etc and then I will insulate adequately between and under the new rafters in the vaulted section - but is there a way to insulate the rear of the two triangular side block wall sections which will just be sat in the loft? Is it as simple as fixing PIR to the blockwork somehow, taping joints and then just leaving the rear face exposed or is there a better / proper way of finishing it off?
TIA
TIA
