AS per the title. Reason for the question is I plan to refurb my kitchen with bathroom above so no requirement for insulation but as the ceiling is down I am going to anyway but just with 50mm, for cost efficiency i plan on getting 100mm thick slabs and cutting them down to 50mm thickness so which is going to be easier more stable stiffer Knauf dritherm32 or ROCKWOOL Thermal Insulation Cavity Batt 37 or somthing else