I'm having thermal and acoustic insulation fitted between the basement/garage and the floor above. There will be two layers of Knauf 90mm Earthwool Frametherm friction fitted between the floor joists (with a 500g Polythene vapour membrane). The Earthwool is a Class 1 fire rated product.
There needs to be a fire resistant barrier between the garage and living room above. I had initially planned to use a cheaper insulation product with less fire resistance, then fireboard + skim below the joists. However the insulation fitters have given me a free upgrade.
So...now I'm having a Class 1 fire rated insulation product fitted, do I still need to use fireboard, or can I use a cheaper board? NB: I only want one layer of board due to the small gap between the ceiling and top of the garage door.
I will run this past building control too, but I find it works better if I give them my thoughts for them to comment on, rather than ask them to specify whats needed.