Fire Separation Wall Code Question

Lmk if there’s a higher sub to submit this

Undertaking situated in Indiana, USA.

Including a 2-story classroom and flex bldg to present church. There’s one new wall that might be abutting present 2-story wing of the church that has a mansard roof. The prevailing portion with the mansard is nineteen'-0" aff. (Blue arrow) The brand new portion of the addition that abuts that is 29'-5" aff. (Crimson arrow)

The score on the hearth wall is 3-hours. For this portion of the firewall, im considering we have to use a 6" steel stud with 3 layers of GWB on all sides.

My questions are… How far above the prevailing mansard roof should that fireplace rated wall prolong? I’ve seen a number of completely different solutions. And what’s the situation we can apply exterior cladding there? Going to be some type of gentle gauge steel. ACM or corrugated. Can complement w struc angle if wanted. If the GWB on the outside aspect wants to increase to the roof, might we apply sheathing immediately excessive of the GWB?

First 12 months at a agency presently, so im fairly silly, (Nearly) any enter appreciated, thanks!