Loft insulation gap

[Rmaynard23]

Hi all,

Currently in the middle of a loft conversion and just adding insulation. I’ve already added 100mm between the rafters with an air gap behind. I’m now coming to add the 50mm on top. My problem is, none of the rafters are level, new ones were bolted to the old ones and so the 100mm is proud of the rafter in places close to 20mm. At present I have been advised to add 20mm battons on top of the joists so that the 50mm can go up in full sheets, but this will mean there is a 10-15mm gap between the two layers of insulation, will this be ok? Thanks

 

[23vc]

Should be ok as long as vapour barrier/foil tape continuous. Incidentally, assume you’re doing this to the previous building regs from a couple of years ago as think the latest is more insulation than that