quick insulation question

[ghostdog]

hi I'm in the process of a loft conversion and have got loads of insulation from work my question is I've got mainly celotex but I've also got some without foil can i mix and match this its to go under my flat roof on my dormer i can post some pics if anyone needs to see what board it is
cheers

 

[freddiemercurystwin]

Well the overall insulation you use needs to be a consistent thickness so if you can achieve that without any air gaps then it will be OK. Just use a foil backed plasterboard to get over the issue that some boards are foil backed and others aren't. Your BCO may raise an eyebrow so maybe mention what you're embarking upon before you do it.