Si while i respect your a building inspector this is what i mean about checking because it always different in certain areas. You are suggesting using 10mm multi foil....by this i assume you mean superquilt? As that is NOT PERMISSABLE in the wakefield area! You can only use that stuff IF you underdraw it then with 50mm kingspan. And the min of 150mm kingspan i refered to i just read off the current drawings i have on the desk...

Now on the 15mm FB to the ceilings....im talking of overboarding the existing ceilings not ripping down to install fireboard....

Like i say, its different areas....