The only fire protection requirement that appears to be prescribed by Chapter 25 is portable extinguishers (2508); no apparent requirement that tires stored indoors per 2509 be protected differently appears to be given.That said, not much greater protection of adjacent properties or the environment would be present if a 2509 pile were ignited inside an unprotected building, except perhaps exterior building walls may limit radiation to exposures to some degree. Therefore, if an exception to IBC 705.8.1 were not applicable for unlimited unprotected openings in an imaginary wall around the pile, construction of exterior wall around the pile as prescribed by IBC 705 may be appropriate in order to offer a similar degree of protection to that of an "indoor pile."
However, where IBC Tables 601 and 602 do not require any fire endurance rating for an exterior wall, the perceived benefit of an exterior wall during a fire event is theoretically zero. As such, it would seem that no wall around the storage could provide nearly an equivalent level of protection to a wall that was destroyed in the first minute of a fire event. Incidentally, for Type IIB or VB construction, this distance could be as little as 10 feet, similar to IFC 315.3.
Whether walls or no walls, it may be reasonable to include the exterior tire storage area(s) managed as indoor storage as part of the building area as regulated by the IBC.
Where the tires are not waste, IFC 102.10 would seem to direct us to specific provisions of Chapter 25 and not apply generic "waste materials" criteria.