sentences:  Fire compartmentalisation is based upon compartments enclosed on all sides to avoid fire and smoke migration beyond each engaged compartment.A non-fire-resistance rated curtain wall prevents the complete compartment (or envelope) from being fire-resistance rated.The provision of firestopping at the joint of the floor slab and curtain wall can still add to the overall fire safety of the building by slowing the advance of the fire in the building interior from floor to floor.