options for 2-hour firewall, spray-on insulation

huangyhg

options for 2-hour firewall, spray-on insulation?
i need advise regarding installation of a 2-hour (level 2) firewall to be installed on the unobstructed "interior" of an exterior wall 18-feet hight by 150-feet long inside a metal building on concrete slab built in 1998.
the interior wall is: exposed veritcal steel beams on 25-foot spacing, and between the beams are vertically-attached plastic-encased insulation. underneith the insulation are horizonal steel purlins(?) which is what the exterior steel panels are secured to via metal screws.
by the way, the building/warehouse is currently occupied :-(
several ideas have been proposed... one is multiple layers of sheetrock attached to new steel studding frame. another was masonry blocks, but steel rebar would need to be installed inside them for strength from floor to celing.
i have been reading that there is a 2-hour rated "spray on" insualtion or else applied via the tradational fill or attach method.
anyone have any suggestions?
thank you, brett slack
check w.r.grace company for their "monokote" spray applied fireproofing.  a 2-hour rating is not that difficult to obtain.  you might have to use some lath, depending on your materials and configuration.
i've seen "no-fire" used also.  while i'm a doubting thomas regarding it's benefit on steel surfaces (my applications),  i suspect it would provide a significant benefit to wood.  
i also wonder what a simple "google" search may turn up?
i spent 12 hours examining google searches, locating many "seller/manufacturers" wares, but i hoped to correspond with an actual user to verify the (many) manufacturers claims.
-brett