Dormer cheek fire proof

[jackboy29]

I need a fire proof dormer cheek on a loft conversion as it is a semi detached house and therefore within 1 m of next door. I think it needs to be 30 minute resistant. My plan was to have tiles, membrane, 18mm WBP plywood, 100 mm stud with celotex insulation between studs, 25mm over studs and plasterboard with skim coat. I have already had it externally tiled and had the building inspector in and he wants 6mm supamax fire boarding installed externally. It means I have to take all the tiles off externally and apparently I can't installed fire board on the inside.

Does this sound right? Is there any reference material anywhere to what constitutes 30 mins resistance?

Are there any alternatives to stripping dormer cheek back again?

Thanks in advance

 

[stuartturbo]

My was tiles, membrane, concrete fire board( heavier than it looks lol) 12mm WBP plywood, 100 mm stud with celotex insulation between studs, that foil stuff then plasterboard with skim coat.

i am really surprised it was not listed in the spec. But they did nearly cause mine to be structurally weak!!!!
I am not aware of any way around it. Try to speak to someone else at BR may be more helpful and suggest alternative