Sheetrock lining fireplace/chimney box

[Shortfinger]

A wood-framed fireplace/chimney is completely inside the heated envelope of a proposed new build. It goes through no floors, just straight up to the roof above, which is framed with scissors trusses on 24 inch centers.

Up in the area where it enters and passes through the roof assembly, what has to be wrapped in sheetrock? The roof will be insulated with 7 inches of sprayfoam shot against the underside of the OSB deck.

The fireplace will be the HeatNGlo Rutherford 50, which will have an insulated doublewall 14" stainless flue.

In the 3D images, the pipe flue is represented by a cylinder representing the flue pipe AND its 2" outer clearance.

 

[DAKSY]

If your install is being inspected, you should talk to the Authority Having Jurisdiction (aka Building Inspector).
You may not have to sheetrock anything, but you WILL need horizontal decks with firestops at every floor level.